A method for preparing an intrinsically flame-retardant, high-efficiency adsorption material for emergency accident scenes

Abstract

A method for preparing an intrinsically flame-retardant, high-efficiency adsorbent material for emergency accident sites, belonging to the field of emergency rescue, is disclosed. The method uses fly ash-based aerogel as a matrix material, KH570 and allyl POSS as modifiers, and 1,4-butanedithiol as a cross-linking agent to prepare the adsorbent material of the present invention. Specifically, the method comprises the following steps: 1) sieving fly ash, adding a sodium hydroxide solution, stirring, and obtaining a filtrate; diluting with deionized water, adjusting the pH, and performing a gel reaction; aging the hydrogel and performing a replacement reaction to obtain a fly ash-based aerogel; 2) preparing a KH570 aqueous solution and dropping it into an ethanol suspension of the fly ash-based aerogel, stirring, adding acetic acid, adjusting the pH, and reacting; 3) mixing the KH570-modified fly ash-based aerogel, 1,4-butanedithiol, and allyl POSS, adding an initiator, and reacting to obtain the intrinsically flame-retardant, high-efficiency adsorbent material for emergency accident sites. The material efficiently adsorbs oily organic matter, reduces the surface saturated vapor pressure of leaked organic compounds, and reduces the risk of secondary disasters such as fire and explosion.

Description

Technical Field

[0001] The invention belongs to the field of emergency rescue, and in particular relates to a method for preparing an intrinsically flame-retardant, high-efficiency adsorption material for emergency accident sites. Background Art

[0002] The number of hazardous chemical sites in my country continues to increase, and the fire safety situation is becoming increasingly severe. According to statistics, from 2020 to 2022, the number of hazardous chemical companies increased from 22,000 to 212,000. Among them, the number of companies involved in key-regulated hazardous chemical processes increased from 11,000 to 14,000, and the quantity of key-regulated hazardous chemicals increased from 160 million tons to 230 million tons, involving nearly 30 types of hazardous chemicals. Furthermore, hazardous chemical sites are prone to chemical leaks, fires, and explosions, resulting in significant casualties. According to statistics, 306 hazardous chemical leaks, fires, and explosions occurred nationwide in 2022, resulting in 93 deaths and disappearances.

[0003] For chemical leaks, emergency treatment can be achieved using methods such as adsorption, filtration membranes, in-situ combustion, and bioremediation. Among the above methods, due to the recyclability of oil and organic solvents, the use of high-efficiency adsorption materials to adsorb and remove oil is considered to be one of the most effective methods.

[0004] Currently, a variety of materials have been used to adsorb and remove petroleum pollutants, including nanosilica-modified cotton fibers, poplar catkin carbon aerogels, reduced graphene aerogels, polyvinyl alcohol / cellulose nanofiber hybrid aerogel microspheres, electrospun cellulose acetate nanofiber mats, and melamine-derived carbon sponges. However, these adsorbents each have limitations in terms of preparation cost, adsorption capacity, recyclability, hydrophobicity, adhesion, and flame retardancy. Therefore, the development of new adsorbents with superior comprehensive performance is crucial for preventing fires caused by oil and organic solvent leaks. Summary of the Invention

[0005] The present invention aims to provide a method for preparing an intrinsically flame-retardant and efficient adsorption material for emergency accident sites. The method uses low-cost fly ash-based aerogel as a matrix material, KH570 (γ-methacryloxypropyltrimethoxysilane) and allyl POSS as modifiers, and 1,4-butanedithiol as a cross-linking agent to prepare the intrinsically flame-retardant and efficient adsorption material for emergency accident sites.

[0006] The allyl POSS is selected from any one or a mixture of any proportions of the following compounds:

[0007]

[0008] Allyl POSS-1: Chinese name PSS-(1-propyl isobutyl acrylate)-heptaisobutyl substituted, CAS number 307531-94-8;

[0009] Allyl POSS-2: Chinese name 1-(allyldimethylsilyloxy)-3,5,7,9,11,13,15-heptacyclopentylpentacyclic-octapolysilsesquioxane, CAS number 352538-78-4;

[0010] Allyl POSS-3: Chinese name PSS-allyl-heptaisobutyl substituted, CAS number 351003-00-4.

[0011] To achieve the above object, the present invention adopts the following technical solutions:

[0012] A method for preparing an intrinsically flame-retardant, high-efficiency adsorption material for emergency accident scenes comprises the following steps:

[0013] Step 1, preparation of fly ash-based aerogel:

[0014] (1) Sieve fly ash with a mesh size of 200-300;

[0015] (2) taking sodium hydroxide solution (mass concentration range 10-90%), mixing fly ash and sodium hydroxide solution in a mass ratio of 1:2, mechanically stirring at 70-90° C. for 3-8 hours, and filtering to obtain a filtrate;

[0016] (3) After diluting the filtrate in a volume ratio of 1:2, the pH value was adjusted to 1-3, and the filtrate was hydrolyzed at room temperature for 8-12 h, and the pH value was adjusted to 5.5-6.5. The hydrogel was allowed to stand for gelation reaction to obtain a hydrogel.

[0017] (4) aging the hydrogel for 1 to 72 hours; performing a displacement reaction, wherein the displacement solvent is water (10 to 90%): ethanol (90 to 10%) solution for 3 times and n-hexane for 1 time; and drying to obtain a fly ash-based aerogel;

[0018] Step 2, preparation of KH570 modified fly ash-based aerogel

[0019] Add ethanol to the fly ash-based aerogel at a mass ratio of 1:(1-10) and stir thoroughly. Prepare a KH570 aqueous solution at a volume ratio of 1:(1-10) and drop it into the ethanol suspension of the fly ash-based aerogel, where the mass ratio of KH570 to fly ash-based aerogel is (1-30)%:(99-70)%, and stir thoroughly. Add acetic acid and adjust the pH to 2-6. React at 50°C for 4-6 hours, wash with water, filter, and take the filter cake for the next reaction.

[0020]

[0021] represents fly ash-based aerogel;

[0022] Step 3: Preparation of intrinsically flame-retardant, high-efficiency adsorption materials for emergency accident scenes

[0023] KH570-modified fly ash-based aerogel is dispersed in toluene at a volume ratio of 1:(1-8). 1,4-Butanedithiol and allyl POSS are added, with the weight ratios being: 1-50% KH570-modified fly ash-based aerogel, 10-30% 1,4-Butanedithiol, and 20-80% allyl POSS, for a total of 100%. AIBN (azobisisobutyronitrile) is added as an initiator at a molar ratio of AIBN to 1,4-Butanedithiol of 1:(200-500). The mixture is reacted at room temperature to 60°C for 6-12 hours. The mixture is filtered, the filter cake is washed with ethanol, and then dried to produce an intrinsically flame-retardant, highly efficient adsorbent material for emergency accident scenes.

[0024] The reaction scheme using allyl POSS-1 as an example is as follows:

[0025]

[0026] Beneficial effects of the present invention:

[0027] 1. Fly ash is a major solid waste generated by my country's thermal power plants. Large quantities of it accumulate, occupying land resources, and forming dust under wind, polluting the environment. Currently, fly ash is primarily reused as a building material, resulting in meager profits. This invention utilizes fly ash waste to prepare functional adsorption materials, significantly increasing the added value of fly ash products and significantly promoting the recycling of fly ash.

[0028] 2. The prepared adsorption material is an organic-inorganic hybrid material. The inorganic phase ensures that the adsorption material is insoluble and stable in a large amount of leaked organic chemicals, and the organic phase improves the compatibility of the adsorption material with leaked organic chemicals. The two work together to ensure the excellent comprehensive performance of the adsorption material.

[0029] 3. The surface of the unmodified fly ash aerogel contains a large number of hydroxyl groups, which is hydrophilic and oleophobic. The modification process of the present invention transforms the fly ash aerogel from polar to non-polar, oleophilic and super-hydrophobic, and greatly improves the oil absorption performance of the product.

[0030] 4. The POSS group (silsesquioxane part) and aerogel both have Si-O skeleton structures and are similar and compatible, forming a structure combining POSS molecular pores and aerogel channels, further significantly improving the adsorption performance.

[0031] 5. The intrinsically flame-retardant high-efficiency adsorption material at the scene of emergency accidents can efficiently adsorb oily organic matter, reducing the surface saturated vapor pressure of leaked organic compounds, thereby reducing the risk of secondary disasters such as fire and explosion.

[0032] 6. The adsorption material after use can be recycled through thermal decomposition activation, which greatly reduces the purchase and use costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a physical picture of the intrinsically flame-retardant, high-efficiency adsorbent material for emergency accident scenes prepared in Example 5;

[0034] Figure 2 This is a scanning electron microscope image of the intrinsically flame-retardant, high-efficiency adsorption material for emergency accident scenes prepared in Example 2 (the spherical particles are POSS groups, and the substrate is a fly ash-based aerogel substrate 50,000 times);

[0035] Figure 3 This is a heat release rate diagram of the intrinsically flame-retardant, high-efficiency adsorption material for emergency accident scenes prepared in Example 2;

[0036] Figure 4 This is a heat release rate diagram of the intrinsically flame-retardant, high-efficiency adsorption material for emergency accident scenes prepared in Example 3;

[0037] Figure 5 This is a heat release rate diagram of the intrinsically flame-retardant, high-efficiency adsorption material for emergency accident scenes prepared in Example 5. DETAILED DESCRIPTION

[0038] The present invention will be further described in detail below with reference to the embodiments. The specific embodiments are for further describing the present invention in detail, but are not intended to limit the scope of protection of the present invention.

[0039] Using gasoline as a model of leaked organic matter, a certain amount of adsorbent material was added to the excess gasoline. The mass was taken out and weighed at regular intervals, and the time point when the mass reached a constant weight was taken as the adsorption saturation time (s). The difference between the total mass at constant weight and the mass of the input adsorbent material was the saturated adsorption mass (g). The ratio of the saturated adsorption mass to the mass of the input adsorbent material was the saturated adsorption capacity per unit mass (g / g). The hydrophobicity of the adsorbent material was measured using a water contact angle meter. After the saturated adsorbent material was heated in a blast oven for desorption, the adsorption test was repeated five times. The ratio of the unit mass adsorption capacity of the fifth time to the first time was the five-time recyclability rate (%). The heat release rate was measured using a microcalorimeter (W / g).

[0040] Comparative Example 1

[0041] Commercially available 300 mesh activated carbon powder. Tap density 0.87g / cm 3 The saturated adsorption capacity per unit mass of gasoline is 0.36 g / g, and the saturated adsorption time is 660 s. The water contact angle is 71°. The five-time recyclability rate is 23%. The heat release rate is 277.3 W / g.

[0042] Comparative Example 2

[0043] Commercially available 300 mesh chromatography silica gel. Tap density 1.12 g / cm 3 The saturated adsorption capacity per unit mass of gasoline is 0.03 g / g, and the saturated adsorption time is greater than 1200 s. The water contact angle is 51°. The five-time recyclability is 9%. The heat release rate is 32.5 W / g.

[0044] Example 1

[0045] Take 200 mesh fly ash, prepare a 10% mass concentration of sodium hydroxide solution, mix the fly ash and sodium hydroxide solution in a mass ratio of 1:2, stir at 70°C for 3 hours, and filter to obtain a filtrate; after diluting the filtrate in a volume ratio of 1:2, adjust the pH to 1, hydrolyze at room temperature for 8 hours, adjust the pH to 5.5, and let it stand for gelation reaction to produce a hydrogel; the hydrogel is aged for 1 hour, replaced with 10% water:90% ethanol solution three times, replaced with n-hexane once, and dried to produce a fly ash-based aerogel;

[0046] Add ethanol to 20g of fly ash-based aerogel at a 1:1 mass ratio and stir thoroughly. Prepare a 1:1 volume ratio of KH570 aqueous solution and add it dropwise to the ethanol suspension of fly ash-based aerogel, with a KH570:fly ash-based aerogel mass ratio of 1%:99%, and stir thoroughly. Add acetic acid and adjust the pH to 2. React at 50°C for 4h, wash with water, filter, and use the filter cake for the next reaction.

[0047] 10g of KH570-modified fly ash-based aerogel was dispersed in toluene at a 1:1 volume ratio. 1,4-Butanedithiol and allyl POSS-1 were added in a mass ratio of 1% KH570-modified fly ash-based aerogel, 20% 1,4-Butanedithiol, and 79% allyl POSS-1. AIBN was added as an initiator at a molar ratio of 1:200. The mixture was reacted at room temperature to 60°C for 6 hours. The mixture was filtered, the filter cake washed three times with ethanol, and then dried to produce an intrinsically flame-retardant, highly efficient adsorption material for emergency accident scenes.

[0048] Tap density 0.33g / cm 3 The saturated adsorption capacity per unit mass of gasoline is 5.37 g / g, and the saturated adsorption time is 370 s. The water contact angle is 165°. The five-time recyclability is 53%. The heat release rate is 166.5 W / g.

[0049] Example 2

[0050] Take 300 mesh fly ash, prepare a 90% mass concentration sodium hydroxide solution, mix the fly ash and sodium hydroxide solution in a mass ratio of 1:2, stir at 70°C for 8 hours, and filter to obtain a filtrate; after diluting the filtrate in a volume ratio of 1:2, adjust the pH to 3, hydrolyze at room temperature for 12 hours, adjust the pH to 6.5, and let it stand for gelation reaction to produce a hydrogel; the hydrogel is aged for 72 hours, replaced with 90% water:10% ethanol solution three times, replaced with n-hexane once, and dried to produce a fly ash-based aerogel;

[0051] Add ethanol to 100g of fly ash-based aerogel at a mass ratio of 1:10 and stir thoroughly. Prepare a KH570 aqueous solution at a volume ratio of 1:10 and dropwise add it to the ethanol suspension of fly ash-based aerogel, with a mass ratio of KH570 to fly ash-based aerogel of 30%:70%. Stir thoroughly. Add acetic acid and adjust the pH to 6. React at 50°C for 6h, wash with water, filter, and use the filter cake for the next reaction.

[0052] 30g of KH570-modified fly ash-based aerogel was dispersed in toluene at a volume ratio of 1:8. 1,4-Butanedithiol and allyl POSS-2 were added in a weight ratio of: 50% KH570-modified fly ash-based aerogel, 30% 1,4-Butanedithiol, and 20% allyl POSS-2. AIBN was added as an initiator at a molar ratio of 1:500. The mixture was reacted at room temperature to 60°C for 12 hours. The mixture was filtered, the filter cake washed three times with ethanol, and then dried to produce an intrinsically flame-retardant, high-efficiency adsorbent material for emergency accident scenes.

[0053] Tap density 0.87g / cm 3 The saturated adsorption capacity per unit mass of gasoline is 12.56 g / g, and the saturated adsorption time is 235 s. The water contact angle is 152°. The five-time recyclability is 89%. The heat release rate is 67.1 W / g.

[0054] The scanning electron microscope image (50000 times) of the intrinsically flame-retardant emergency accident scene high-efficiency adsorption material prepared in Example 2 is as follows Figure 2 As shown, the heat release rate is Figure 3 shown.

[0055] Example 3

[0056] Take 200 mesh fly ash, prepare a 30% mass concentration of sodium hydroxide solution, mix the fly ash and sodium hydroxide solution in a mass ratio of 1:2, stir at 70°C for 6 hours, and filter to obtain a filtrate; after diluting the filtrate in a volume ratio of 1:2, adjust the pH to 2, hydrolyze at room temperature for 10 hours, adjust the pH to 6.0, and let it stand for gelation reaction to produce a hydrogel; the hydrogel is aged for 36 hours, replaced with 80% water:20% ethanol solution three times, replaced with n-hexane once, and dried to produce a fly ash-based aerogel;

[0057] Add ethanol to 50g of fly ash-based aerogel at a mass ratio of 1:8 and stir thoroughly. Prepare a KH570 aqueous solution at a volume ratio of 1:5 and dropwise add it to the ethanol suspension of fly ash-based aerogel, with a mass ratio of KH570 to fly ash-based aerogel of 10%:90%. Stir thoroughly. Add acetic acid and adjust the pH to 5. React at 50°C for 4h, wash with water, filter, and use the filter cake for the next reaction.

[0058] 20g of KH570-modified fly ash-based aerogel was dispersed in toluene at a volume ratio of 1:6. 1,4-Butanedithiol and allyl POSS-3 were added in a weight ratio of 10% KH570-modified fly ash-based aerogel, 10% 1,4-Butanedithiol, and 80% allyl POSS-3. AIBN was added as an initiator at a molar ratio of 1:300. The mixture was reacted at room temperature to 60°C for 12 hours. The mixture was filtered, the filter cake washed three times with ethanol, and then dried to produce an intrinsically flame-retardant, highly efficient adsorbent material for emergency accident scenes.

[0059] Tap density 0.52g / cm 3 The saturated adsorption capacity per unit mass of gasoline is 23.89 g / g, and the saturated adsorption time is 190 s. The water contact angle is 159°. The five-time recyclability is 77%. The heat release rate is 85.2 W / g.

[0060] The heat release rate of the intrinsically flame-retardant emergency accident scene high-efficiency adsorption material prepared in Example 3 is as follows: Figure 4 shown.

[0061] Example 4

[0062] Take 200 mesh fly ash, prepare a 50% mass concentration sodium hydroxide solution, mix the fly ash and sodium hydroxide solution in a mass ratio of 1:2, stir at 70°C for 5 hours, and filter to obtain a filtrate; after diluting the filtrate in a volume ratio of 1:2, adjust the pH to 2, hydrolyze at room temperature for 9 hours, adjust the pH to 6.5, and let it stand for gelation reaction to produce a hydrogel; the hydrogel is aged for 52 hours, replaced with 50% water:50% ethanol solution three times, replaced with n-hexane once, and dried to produce a fly ash-based aerogel;

[0063] Add ethanol to 20g of fly ash-based aerogel at a mass ratio of 1:5 and stir thoroughly. Prepare a KH570 aqueous solution at a volume ratio of 1:8 and dropwise add it to the ethanol suspension of fly ash-based aerogel, with a mass ratio of KH570 to fly ash-based aerogel of 12%:88%, stirring thoroughly. Add acetic acid and adjust the pH to 3. React at 50°C for 6h, wash with water, filter, and use the filter cake for the next reaction.

[0064] 10g of KH570-modified fly ash-based aerogel was dispersed in toluene at a volume ratio of 1:3. 1,4-Butanedithiol and allyl POSS (a mixture of allyl POSS-1 and allyl POSS-2, with a molar ratio of allyl POSS-1:allyl POSS-2 of 3:2) were added. The weight ratios were: 30% KH570-modified fly ash-based aerogel, 20% 1,4-Butanedithiol, and 50% allyl POSS. AIBN was added as an initiator at a molar ratio of 1:200. The mixture was reacted at room temperature to 60°C for 8 hours. The mixture was filtered, the filter cake washed three times with ethanol, and then dried to produce an intrinsically flame-retardant, high-efficiency adsorption material for emergency accident scenes.

[0065] Tap density 0.61g / cm 3 The saturated adsorption capacity per unit mass of gasoline is 36.21 g / g, and the saturated adsorption time is 130 s. The water contact angle is 161°. The five-time recyclability is 86%. The heat release rate is 77.6 W / g.

[0066] Example 5

[0067] Take 300 mesh fly ash, prepare 80% mass concentration of sodium hydroxide solution, mix fly ash: sodium hydroxide solution at a mass ratio of 1:2, stir at 90°C for 5 hours, and filter to obtain a filtrate; after diluting the filtrate at a volume ratio of 1:2, adjust the pH to 1, hydrolyze at room temperature for 11 hours, adjust the pH to 6.5, and let it stand for gelation reaction to produce a hydrogel; the hydrogel is aged for 24 hours, replaced with 20% water:80% ethanol solution three times, replaced with n-hexane once, and dried to produce a fly ash-based aerogel;

[0068] Add ethanol to 100g of fly ash-based aerogel at a mass ratio of 1:8 and stir thoroughly. Prepare a KH570 aqueous solution at a volume ratio of 1:3 and dropwise add it to the ethanol suspension of fly ash-based aerogel, with a mass ratio of KH570 to fly ash-based aerogel of 25%:75%. Stir thoroughly. Add acetic acid and adjust the pH to 5. React at 50°C for 6h, wash with water, filter, and use the filter cake for the next reaction.

[0069] 20g of KH570-modified fly ash-based aerogel was dispersed in toluene at a volume ratio of 1:5. 1,4-Butanedithiol and allyl POSS (a mixture of allyl POSS-1 and allyl POSS-3, with a molar ratio of allyl POSS-1:allyl POSS-3 of 2:1) were added. The weight ratios were: 50% KH570-modified fly ash-based aerogel, 20% 1,4-Butanedithiol, and 30% allyl POSS. AIBN was added as an initiator at a molar ratio of AIBN to 1,4-Butanedithiol of 1:200. The mixture was reacted at room temperature to 60°C for 7 hours. The mixture was filtered, the filter cake washed three times with ethanol, and then dried to produce an intrinsically flame-retardant, highly efficient adsorption material for emergency accident scenes.

[0070] Tap density 0.73g / cm 3 The saturated adsorption capacity per unit mass of gasoline is 28.68 g / g, and the saturated adsorption time is 60 s. The water contact angle is 155°. The five-time recyclability is 93%. The heat release rate is 39.7 W / g.

[0071] The actual material of the intrinsically flame-retardant emergency accident scene high-efficiency adsorption material prepared in Example 5 is as follows Figure 1 As shown, the heat release rate of the adsorbent material Figure 5 shown.

[0072] Example 6

[0073] Take 300 mesh fly ash, prepare a 60% mass concentration of sodium hydroxide solution, mix the fly ash and sodium hydroxide solution in a mass ratio of 1:2, stir at 70°C for 7 hours, and filter to obtain a filtrate; after diluting the filtrate in a volume ratio of 1:2, adjust the pH to 3, hydrolyze at room temperature for 10 hours, adjust the pH to 5.5, and let it stand for gelation reaction to produce a hydrogel; the hydrogel is aged for 60 hours, replaced with 90% water:10% ethanol solution three times, replaced with n-hexane once, and dried to produce a fly ash-based aerogel;

[0074] Add ethanol to 80g of fly ash-based aerogel at a mass ratio of 1:3 and stir thoroughly. Prepare a KH570 aqueous solution at a volume ratio of 1:9 and dropwise add it to the ethanol suspension of fly ash-based aerogel, with a mass ratio of KH570 to fly ash-based aerogel of 15%:85%. Stir thoroughly. Add acetic acid and adjust the pH to 3. React at 50°C for 4h, wash with water, filter, and use the filter cake for the next reaction.

[0075] 20g of KH570-modified fly ash-based aerogel was dispersed in toluene at a 1:1 volume ratio. 1,4-Butanedithiol and allyl POSS (a mixture of allyl POSS-1, allyl POSS-2, and allyl POSS-3, with a molar ratio of allyl POSS-1:allyl POSS-2:allyl POSS-3 of 1:1:1) were added. The mass ratios were: 20% KH570-modified fly ash-based aerogel, 20% 1,4-Butanedithiol, and 60% allyl POSS. AIBN was added as an initiator at a molar ratio of AIBN to 1,4-Butanedithiol of 1:350. The mixture was reacted at room temperature to 60°C for 7 hours. The mixture was filtered, the filter cake washed three times with ethanol, and then dried to produce an intrinsically flame-retardant, highly efficient adsorption material for emergency accident scenes.

[0076] Tap density 0.57g / cm 3 The saturated adsorption capacity per unit mass of gasoline is 23.89 g / g, and the saturated adsorption time is 100 s. The water contact angle is 150°. The five-time recyclability is 83%. The heat release rate is 126.8 W / g.

Claims

1. A method for preparing an intrinsically flame-retardant, efficient adsorption material for emergency accident sites, characterized in that: Using fly ash-based aerogel as the matrix material, KH570 and allyl POSS as modifiers, and 1,4-butanedithiol as a cross-linking agent, an intrinsically flame-retardant and highly efficient adsorption material for emergency accident sites was prepared. The allyl POSS is selected from any one or a mixture of any proportions of the following compounds: ； The following steps are involved: Step 1, preparation of fly ash-based aerogel: (1) Sieve fly ash with a mesh size of 200-300; (2) Mix the sodium hydroxide solution with fly ash, stir for 3-8 hours, and then filter to obtain the filtrate; (3) After adding deionized water to dilute the filtrate, adjust the pH to 1-3, hydrolyze at room temperature, and let it stand for gelation reaction to prepare a hydrogel; (4) subjecting the hydrogel to aging, replacement reaction, and drying to obtain fly ash-based aerogel; Step 2, preparation of KH570 modified fly ash-based aerogel Add ethanol to the fly ash-based aerogel and stir thoroughly; prepare a KH570 aqueous solution and drop it into the ethanol suspension of the fly ash-based aerogel, stir thoroughly, add acetic acid, adjust the pH value, react, wash with water, filter, and take the filter cake for the next reaction; Step 3: Preparation of intrinsically flame-retardant, high-efficiency adsorption materials for emergency accident scenes KH570 modified fly ash-based aerogel is dispersed in toluene, 1,4-butanedithiol, allyl POSS, and azobisisobutyronitrile are added as an initiator, and the mixture is reacted, filtered, the filter cake is washed, and dried to obtain an intrinsically flame-retardant and efficient adsorption material for emergency accident sites.

2. The method for preparing an intrinsically flame-retardant, efficient adsorption material for emergency accident scenes according to claim 1, characterized in that: In step 1 (2), the fly ash: sodium hydroxide solution is mixed in a mass ratio of 1:2, stirred at 70-90° C. for 3-8 hours, and then filtered to obtain a filtrate.

3. The method for preparing an intrinsically flame-retardant, efficient adsorption material for emergency accident scenes according to claim 1, characterized in that: In step 1 (3), the volume ratio of filtrate to deionized water is 1:

2. After diluting the filtrate, the pH is adjusted to 1-3, and hydrolysis is carried out at room temperature for 8-12 hours. The pH is adjusted to 5.5-6.5, and the mixture is allowed to stand for gelation reaction to obtain a hydrogel.

4. The method for preparing an intrinsically flame-retardant, efficient adsorbent material for emergency accident scenes according to claim 1, characterized in that: In step 1 (4), the replacement solvent is a 10-90% water: 90-10% ethanol solution, which is replaced three times and replaced once with n-hexane.

5. The method for preparing an intrinsically flame-retardant, efficient adsorbent material for emergency accident scenes according to claim 1, characterized in that: In step 2, ethanol is added to the fly ash-based aerogel at a mass ratio of 1:1-10 and stirred thoroughly; a KH570 aqueous solution is prepared at a volume ratio of 1:1-10 and added dropwise to the ethanol suspension of the fly ash-based aerogel, wherein the mass ratio of KH570 to fly ash-based aerogel is 1-30%:99-70%.

6. The method for preparing an intrinsically flame-retardant, efficient adsorbent material for emergency accident scenes according to claim 1, characterized in that: In the step 3, the mixture of KH570 modified fly ash-based aerogel, 1,4-butanedithiol, and allyl POSS comprises the following proportions by mass: 1-50% of KH570 modified fly ash-based aerogel, 10-30% of 1,4-butanedithiol, and 20-80% of allyl POSS, totaling 100%.

7. The method for preparing an intrinsically flame-retardant, efficient adsorbent material for emergency accident scenes according to claim 1, characterized in that: In the step 3, the molar ratio of azobisisobutyronitrile to 1,4-butanedithiol is 1:200-500.

8. An intrinsically flame-retardant, efficient adsorption material for emergency accident scenes, prepared by the preparation method according to any one of claims 1 to 7.

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