Preparation method of nano silicon dioxide with high micropore structure

Abstract

The invention discloses a preparation method of nano-silica with a high microporous structure, and belongs to the technical field of nano-silica preparation, and the preparation method comprises the following steps: S1, hydrolysis reaction: taking silicate ester as a silicon source, adding water according to a molar ratio of water to silicate ester of 15-20, adding an anionic modifier into the water according to a mass ratio of the anionic modifier to silicate ester of 1: 10-1: 50, and carrying out hydrolysis reaction for 2-3 hours; adjusting the pH value of the solution to 4.0-6.0 by using hydrochloric acid, and carrying out hydrolysis reaction on silicate ester at the temperature of 30 DEG C for 1 hour to obtain a solution containing silanol and alcohols; and S2, dealcoholization reaction: placing the solution containing silanol and alcohol in a rotary evaporator, evaporating under a reduced pressure condition to gradually volatilize the alcohol, and removing the alcohol after the alcohol is completely volatilized to form a silicon dioxide network structure. The nano silicon dioxide prepared by the method disclosed by the invention has the advantages of small pore diameter, more uniform pore structure and higher specific surface area.

Description

Technical Field

[0001] This invention relates to the field of nano-silica preparation technology, and more specifically to a method for preparing nano-silica with a highly microporous structure. Background Technology

[0002] With the rapid development of nanotechnology, nano-silica, due to its unique physicochemical properties, has been widely used in numerous fields, such as catalysts, adsorbents, sensors, and drug carriers. The performance of nano-silica largely depends on its pore structure, including pore size, porosity, and specific surface area. Highly microporous nano-silica possesses a large specific surface area and abundant pores, which can significantly improve its adsorption capacity, catalytic activity, and reaction rate, thus demonstrating greater application potential in related fields.

[0003] Currently, the main methods for preparing nano-silica include the sol-gel method, precipitation method, and gas-phase method. Among them, the sol-gel method is a commonly used method, which prepares nano-silica through the hydrolysis and condensation reactions of silicon source compounds. However, nano-silica prepared by the traditional sol-gel method has some shortcomings. For example, the hydrolysis and condensation reactions often occur simultaneously, resulting in a relatively dense silica network structure with fewer pores and a lower specific surface area, which is difficult to meet the requirements of some high-performance applications. In addition, the traditional preparation method cannot precisely control the pore size of nano-silica, making it difficult to achieve precise control of the pore size and limiting its application in specific fields. To overcome these shortcomings, this invention provides a method for preparing nano-silica with a highly microporous structure. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention aims to provide a method for preparing nano-silica with a high microporous structure. The nano-silica prepared by the method has small pore size, more uniform pore structure and higher specific surface area.

[0005] The objective of this invention is achieved through the following technical solution: A method for preparing highly microporous nano-silica includes the following steps: S1. Hydrolysis reaction: Using silicate ester as silicon source, water is added, with a molar ratio of water to silicate ester of 15-20. An anionic modifier is then added to the water, wherein the mass ratio of the anionic modifier to the silicate ester is 1:10 to 1:50. The pH of the solution is adjusted to 4.0-6.0 using hydrochloric acid. The silicate ester undergoes a hydrolysis reaction at a temperature of 30°C for 1 hour, yielding a solution containing silanols and alcohols. S2, De-alcoholization reaction: The solution containing silanol and alcohol is placed in a rotary evaporator. The temperature of the rotary evaporator is set to 40-60℃ and the pressure to 10-20 mmHg. Evaporation is carried out under reduced pressure to allow the alcohol to gradually volatilize. After the alcohol has completely volatilized, it is removed. S3, condensation reaction S31. Preparation of template solution: At room temperature, dissolve the template agent in deionized water, stir evenly, add ethanol, and continue stirring for 30 minutes to ensure that the template agent is completely dissolved and evenly dispersed to obtain the template solution; S32. Pass the silanol solution through an anion exchange column to allow the anion modifier to exchange with the anions on the resin in the anion exchange column, thereby removing the anion modifier from the silanol solution. After removal, ammonia is added as a catalyst, the pH is adjusted to 8.0-9.0, the temperature of the solution is raised to 60°C, the template solution is added, and stirring is continued for 1 hour to carry out a condensation reaction to prevent excessive condensation of the network structure and to form a silica network structure. S4. Termination of reaction: After the silica network structure is formed, hydrochloric acid solution is added to adjust the pH value of the solution to 7, thereby terminating the condensation reaction and obtaining nano silica solution. S5. Desolution: The nano-silica solution is centrifuged, washed three times with ethanol and deionized water respectively, and the resulting gel is dried at 60°C for 6 hours. S6. Calcination: After drying, the temperature is increased to 600℃ at 5℃ / min in air atmosphere and calcined for 2h to remove the template agent and organic impurities, thereby obtaining the highly microporous nano-silica.

[0006] Furthermore, the silicate ester is one of methyl silicate and ethyl silicate.

[0007] Furthermore, in step S2, the corresponding alcohols are recovered by an alcohol recovery device.

[0008] Furthermore, the template agent is one of P123 and hexadecyltrimethylammonium bromide (CTAB).

[0009] Furthermore, in step S32, during the stirring process for another hour, functionalized precursors are gradually added to form a functionalized silica network structure.

[0010] Furthermore, methyltriethoxysilane is used as the functional group precursor, and during the stirring process, methyltriethoxysilane is gradually added to form a silica network structure with methyl functionalization.

[0011] Further, in step S1, the anionic modifier includes at least one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium dodecylbenzene sulfonate, sodium dibutylnaphthalene sulfonate, sodium dodecyl diphenyl ether sulfonate, sodium stearate, N,N-dihydroxyethyl lauramide, and sodium isotridecyl ether sulfate.

[0012] Further, step S5 involves cooling: after calcination, the mixture is allowed to cool naturally to room temperature to prevent particle agglomeration.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The method for preparing nano-silica with high microporous structure provided by the present invention uses silicate ester as raw material. In addition to the main nano-silica, there are also corresponding alcohols as by-products, which can be recycled and utilized through an alcohol recovery device. In step S1, the hydrolysis reaction conditions are controlled as follows: the molar ratio of water to silicate ester is 15–20, the mass ratio of the nano-silicone rubber particles to the silicate ester is 1:10 to 1:50, ammonia is added as a catalyst at 30°C, and hydrochloric acid is used to adjust the pH of the solution to 4.0–6.0, which is more conducive to the hydrolysis reaction. Simultaneously, an anionic modifier is added in step S1. The hydrophobic end of the anionic modifier adsorbs onto the surface of the silanol to form an interfacial phase. Due to the mutual repulsion of the hydrophobic groups and the steric hindrance effect, the interfacial phase can inhibit the aggregation of small molecule silanols and prevent the condensation reaction of silanols. In addition, the hydrogen bonding between the anionic modifier and the silanol hydroxyl group protects the silanol hydroxyl group to a certain extent, further preventing the condensation reaction of silanols. Because the above scheme can delay the condensation reaction, the condensation reaction is relatively delayed. Therefore, the concentration of silanol after hydrolysis can be increased to a greater extent. Passing the silanol solution through an anion exchange column allows the anion modifier to exchange with the anions on the resin in the column, thereby removing the anion modifier from the silanol solution. After removal, the silica network structure formed by the condensation reaction becomes looser with more pores, but the pore size is relatively smaller. Due to the smaller pore size and more pores, the specific surface area of ​​the silica network structure increases, resulting in a mesoporous ordered structure with a high specific surface area (BET specific surface area > 800 m²). 2 / g; small pore size, between 1~20nm. Adjusting the pH to 8.0-9.0 during the condensation reaction accelerates the condensation reaction of silanols. The presence of alcohols dilutes the concentration of silanols, thus slowing down the condensation reaction rate between silanols. (2) The method for preparing nano-silica with high microporous structure provided by the present invention, in step S32, ammonia water is added as a catalyst, the pH is adjusted to 8.0-9.0, and the temperature of the solution is increased to 60°C to accelerate the condensation reaction. During the stirring process for 1 hour, functional group precursors are gradually added to form a silicon dioxide network structure with functional groups. For example, during the condensation reaction, methyltriethoxysilane is added. As the proportion of methyltriethoxysilane increases, the increase of methyl functional groups will increase the pore size in the network structure. Because methyl occupies part of the space, the connection between silicon-oxygen-silicon bonds becomes relatively loose, thereby increasing the pore size and controlling the pore size of nano-silica. Detailed Implementation

[0014] The present invention will now be further described in conjunction with specific embodiments. It should be noted that, without conflict, the embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0015] Example 1

[0016] The method for preparing highly microporous nano-silica provided in this embodiment includes the following steps: S1. Hydrolysis reaction: Using silicate ester as the silicon source, water is added, with a molar ratio of water to silicate ester of 15. Anionic modifier sodium dodecyl sulfate is then added to the water, wherein the mass ratio of sodium dodecyl sulfate to silicate ester is 1:10 to 1:50. The pH of the solution is adjusted to 4.0 using hydrochloric acid. The silicate ester undergoes hydrolysis reaction at a temperature of 30°C for 1 hour, yielding a solution containing silanols and alcohols. S2, De-alcoholization reaction: The solution containing silanol and alcohol is placed in a rotary evaporator. The temperature of the rotary evaporator is set to 40℃ and the pressure to 10 mmHg. Evaporation is carried out under reduced pressure to allow the alcohol to gradually volatilize. After the alcohol has completely volatilized, it is removed. S3, condensation reaction S31. Preparation of template solution: At room temperature, dissolve 0.5g of template agent P123 in 70mL of deionized water, stir well, add 10mL of ethanol, and continue stirring for 30 minutes to ensure that template agent P123 is completely dissolved and uniformly dispersed to obtain template solution. S32. Pass the silanol solution through an anion exchange column to allow the anion modifier sodium dodecyl sulfate to exchange with the anions on the resin in the anion exchange column, thereby removing the anion modifier sodium dodecyl sulfate from the silanol solution. After removal, ammonia water is added as a catalyst, the pH is adjusted to 8.0, the temperature of the solution is raised to 60°C, the template solution is added, and stirring is continued for 1 hour to carry out the condensation reaction, preventing the network structure from over-condensing and forming a silica network structure. S4. Termination of reaction: After the formation of the silica network structure, add hydrochloric acid solution to adjust the pH value of the solution to 7, thereby terminating the condensation reaction and obtaining nano silica solution. S5. Desolution: Centrifuge the nano-silica solution, wash it three times with ethanol and deionized water respectively, and dry the resulting gel at 60°C for 6 hours. S6. Calcination: After drying, the temperature is increased to 600℃ at 5℃ / min in air atmosphere and calcined for 2h to remove template agent P123 and organic impurities, thus obtaining nano-silica with a highly microporous structure.

[0017] In this embodiment, the molar ratio of water to silicate ester is 15-20, and its function is as follows: (1) Smaller pore size: When the water / TEOS molar ratio (R) increases, the hydrolysis reaction is more complete and more silanols are generated. Since the condensation reaction is relatively delayed, the network structure formed is more loose and has more pores, but the pore size is relatively small. This is because a large amount of silanol will form more small pores during the condensation process.

[0018] (2) Higher specific surface area: Due to smaller pore size and more pores, the specific surface area of ​​the material will increase. Specific surface area is the sum of the surface area of ​​the pores inside the material. The smaller the pore size and the more pores, the higher the specific surface area.

[0019] The relationship between pore structure and specific surface area is as follows: Specific surface area refers to the total surface area per unit mass of material, including both the outer and inner surfaces. For nanomaterials, especially porous materials, the contribution of the inner surface is often much greater than that of the outer surface.

[0020] The presence of mesopores (pore size between 2-50 nanometers) and macropores (pore size greater than 50 nanometers) results in a large number of channels and pores within the material. The inner walls of these pores also contribute to the material's surface area, thus significantly increasing the total specific surface area.

[0021] In this embodiment, the template agent plays the following role: Adding a template agent to the condensation reaction guides the formation of pores. Because the template agent occupies space, it prevents excessive condensation of the silicon-oxygen-silicon bond network, thus forming more pores. These template agents can be removed after the reaction by calcination or solvent extraction, leaving behind even more pores.

[0022] In this embodiment, the hydrolysis reaction is preferentially carried out at a temperature of 30°C, and the condensation reaction is carried out at a temperature of 60°C for the following reasons: By employing a stepwise heating method, the hydrolysis reaction is first carried out at a lower temperature to generate sufficient silanols, and then the temperature is gradually increased to accelerate the condensation reaction. This method can generate more silanols during the hydrolysis stage, and then accelerate the condensation reaction by increasing the temperature during the condensation stage. This method can effectively control the formation of nano-silica pores during the condensation reaction.

[0023] In this embodiment, the use of a template agent can optimize the uniformity of the pore structure. For example, combining cationic surfactants (such as CTAB) and nonionic surfactants (such as P123) can form a more uniform pore structure.

[0024] Example 2

[0025] The method for preparing highly microporous nano-silica provided in this embodiment includes the following steps: S1. Hydrolysis reaction: Using silicate ester as the silicon source, water is added, with a molar ratio of water to silicate ester of 18. Sodium dodecylbenzenesulfonate, an anionic modifier, is then added to the water, wherein the mass ratio of sodium dodecylbenzenesulfonate to silicate ester is 1:10 to 1:50. The pH of the solution is adjusted to 5.0 using hydrochloric acid. The silicate ester undergoes a hydrolysis reaction at a temperature of 30°C for 1 hour, yielding a solution containing silanols and alcohols. S2, De-alcoholization reaction: The solution containing silanol and alcohol is placed in a rotary evaporator. The temperature of the rotary evaporator is set to 50℃ and the pressure to 15 mmHg. Evaporation is carried out under reduced pressure to allow the alcohol to gradually volatilize. After the alcohol has completely volatilized, it is removed. S3, condensation reaction S31. Preparation of template solution: At room temperature, dissolve 0.5g of the template agent cetyltrimethylammonium bromide (CTAB) in 70mL of deionized water, stir well, add 10mL of ethanol, and continue stirring for 30 minutes to ensure that the template agent cetyltrimethylammonium bromide is completely dissolved and uniformly dispersed to obtain the template solution. S32. Pass the silanol solution through an anion exchange column to allow the sodium dodecylbenzenesulfonate anion modifier to exchange with the anions on the resin in the anion exchange column, thereby removing the sodium dodecylbenzenesulfonate anion modifier from the silanol solution. After removal, ammonia water is added as a catalyst, the pH is adjusted to 8.5, the temperature of the solution is raised to 60°C, the template solution is added, and stirring is continued for 1 hour to carry out the condensation reaction, preventing excessive condensation of the network structure and forming a silica network structure. S4. Termination of reaction: After the formation of the silica network structure, add hydrochloric acid solution to adjust the pH value of the solution to 7, thereby terminating the condensation reaction and obtaining nano silica solution. S5. Desolution: Centrifuge the nano-silica solution, wash it three times with ethanol and deionized water respectively, and dry the resulting gel at 60°C for 6 hours. S6. Calcination: After drying, the temperature is increased to 600℃ at 5℃ / min in air atmosphere and calcined for 2h to remove the template agent hexadecyltrimethylammonium bromide and organic impurities, thus obtaining nano-silica with a highly microporous structure.

[0026] Example 3

[0027] The method for preparing highly microporous nano-silica provided in this embodiment includes the following steps: S1. Hydrolysis reaction: Using silicate ester as the silicon source, water is added, with a molar ratio of water to silicate ester of 20. Sodium dodecylbenzenesulfonate, an anionic modifier, is then added to the water, wherein the mass ratio of sodium dodecylbenzenesulfonate to silicate ester is 1:10 to 1:50. The pH of the solution is adjusted to 6.0 using hydrochloric acid. The silicate ester undergoes a hydrolysis reaction at a temperature of 30°C for 1 hour, yielding a solution containing silanols and alcohols. S2, De-alcoholization reaction: The solution containing silanol and alcohol is placed in a rotary evaporator. The temperature of the rotary evaporator is set to 60℃ and the pressure to 20 mmHg. Evaporation is carried out under reduced pressure to allow the alcohol to gradually evaporate. After the alcohol has evaporated completely, it is removed. S3, condensation reaction S31. Preparation of template solution: At room temperature, dissolve 0.5g of the template agent hexadecyltrimethylammonium bromide in 70mL of deionized water, stir well, add 10mL of ethanol, and continue stirring for 30 minutes to ensure that the template agent hexadecyltrimethylammonium bromide is completely dissolved and uniformly dispersed to obtain the template solution. S32. Pass the silanol solution through an anion exchange column to allow the sodium dodecylbenzenesulfonate anion modifier to exchange with the anions on the resin in the anion exchange column, thereby removing the sodium dodecylbenzenesulfonate anion modifier from the silanol solution. After removal, ammonia water is added as a catalyst, the pH is adjusted to 9.0, the temperature of the solution is raised to 60°C, the template solution is added, and stirring is continued for 1 hour to carry out the condensation reaction, preventing the network structure from over-condensing and forming a silica network structure. S4. Termination of reaction: After the formation of the silica network structure, add hydrochloric acid solution to adjust the pH value of the solution to 7, thereby terminating the condensation reaction and obtaining nano silica solution. S5. Desolution: Centrifuge the nano-silica solution, wash it three times with ethanol and deionized water respectively, and dry the resulting gel at 60°C for 6 hours. S6. Calcination: After drying, the temperature is increased to 600℃ at 5℃ / min in air atmosphere and calcined for 2h to remove the template agent hexadecyltrimethylammonium bromide and organic impurities, thus obtaining nano-silica with a highly microporous structure.

[0028] Example 4

[0029] The method for preparing highly microporous nano-silica provided in this embodiment includes the following steps: S1. Hydrolysis reaction: Using silicate ester as silicon source, water is added, with a molar ratio of water to silicate ester of 20. Anionic modifier sodium dibutylnaphthalene sulfonate is then added to the water, wherein the mass ratio of sodium dibutylnaphthalene sulfonate to silicate ester is 1:10 to 1:50. The pH of the solution is adjusted to 6.0 using hydrochloric acid. The silicate ester undergoes hydrolysis reaction at a temperature of 30°C for 1 hour, yielding a solution containing silanols and alcohols. S2, De-alcoholization reaction: The solution containing silanol and alcohol is placed in a rotary evaporator. The temperature of the rotary evaporator is set to 60℃ and the pressure to 20 mmHg. Evaporation is carried out under reduced pressure to allow the alcohol to gradually evaporate. After the alcohol has evaporated completely, it is removed. S3, condensation reaction S31. Preparation of template solution: At room temperature, dissolve 0.5g of the template agent hexadecyltrimethylammonium bromide in 70mL of deionized water, stir well, add 10mL of ethanol, and continue stirring for 30 minutes to ensure that the template agent hexadecyltrimethylammonium bromide is completely dissolved and uniformly dispersed to obtain the template solution. S32. The silanol solution is passed through an anion exchange column, allowing the anion modifier sodium dibutylnaphthalene sulfonate to exchange with the anions on the resin in the anion exchange column, thereby removing the anion modifier sodium dibutylnaphthalene sulfonate from the silanol solution. After removal, ammonia is added as a catalyst, the pH is adjusted to 9.0, the solution temperature is raised to 60°C, a template solution is added, and stirring is continued for 1 hour to carry out a condensation reaction, preventing excessive condensation of the network structure and forming a silica network structure. In addition, methyltriethoxysilane is gradually added as a functional group precursor during stirring to form a silica network structure with methyl functionalization. S4. Termination of reaction: After the formation of the silica network structure, add hydrochloric acid solution to adjust the pH value of the solution to 7, thereby terminating the condensation reaction and obtaining nano silica solution. S5. Desolution: Centrifuge the nano-silica solution, wash it three times with ethanol and deionized water respectively, and dry the resulting gel at 60°C for 6 hours. S6. Calcination: After drying, the temperature is increased to 600℃ at 5℃ / min in air atmosphere and calcined for 2h to remove the template agent hexadecyltrimethylammonium bromide and organic impurities, thus obtaining nano-silica with a highly microporous structure.

[0030] In this embodiment, during step S32, while stirring for another hour, the functional group precursor methyltriethoxysilane is gradually added to form a silica network structure with methyltriethoxysilane. In this embodiment, the role of adding methyltriethoxysilane during the condensation reaction is to increase the proportion of methyltriethoxysilane to introduce more methyl functional groups. These methyl functional groups will occupy a certain space to prevent the silicon-oxygen-silicon bond network from over-condensing, thereby forming more pores. It can also introduce the following functional group precursor.

[0031] During the condensation reaction of tetraethyl orthosilicate, different functional groups are introduced by adding specific functional group precursors. These precursors react with tetraethyl orthosilicate, resulting in silica with a surface bearing these specific functional groups. These functional groups can be attached to the silica surface via chemical bonds (such as Si-O-Si bonds). Various functional groups, such as amino, epoxy, mercapto, and carboxyl groups, can be introduced as needed, thereby endowing silica with different chemical properties.

[0032] For example: Amino functional group: It can be used as a functional group precursor by adding 3-aminopropyltriethoxysilane (APTES).

[0033] Si(OC2H5)4 + APTES + H2O → SiO2−NH2+ (byproduct) Epoxy functional group: It can be used as a functional group precursor by adding γ-glycidoxypropyltrimethoxysilane (GPTMS).

[0034] Si(OC2H5)4 + GPTMS + H2O → SiO2−epoxy group + byproducts The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing highly microporous nano-silica, characterized in that, Includes the following steps: S1. Hydrolysis reaction: Using silicate ester as silicon source, water is added, with a molar ratio of water to silicate ester of 15-20. An anionic modifier is then added to the water, wherein the mass ratio of the anionic modifier to the silicate ester is 1:10 to 1:

50. The pH of the solution is adjusted to 4.0-6.0 using hydrochloric acid. The silicate ester undergoes a hydrolysis reaction at a temperature of 30°C for 1 hour, yielding a solution containing silanols and alcohols. S2, De-alcoholization reaction: The solution containing silanol and alcohol is placed in a rotary evaporator. The temperature of the rotary evaporator is set to 40-60℃ and the pressure to 10-20 mmHg. Evaporation is carried out under reduced pressure to allow the alcohol to gradually volatilize. After the alcohol has completely volatilized, it is removed. S3, condensation reaction S31. Preparation of template solution: At room temperature, dissolve the template agent in deionized water, stir evenly, add ethanol, and continue stirring for 30 minutes to ensure that the template agent is completely dissolved and evenly dispersed to obtain the template solution; S32. Pass the silanol solution through an anion exchange column to allow the anion modifier to exchange with the anions on the resin in the anion exchange column, thereby removing the anion modifier from the silanol solution. After removal, ammonia is added as a catalyst, the pH is adjusted to 8.0-9.0, the temperature of the solution is raised to 60°C, the template solution is added, and stirring is continued for 1 hour to carry out a condensation reaction to prevent excessive condensation of the network structure and to form a silica network structure. S4. Termination of reaction: After the silica network structure is formed, hydrochloric acid solution is added to adjust the pH value of the solution to 7, thereby terminating the condensation reaction and obtaining nano silica solution. S5. Desolution: The nano-silica solution is centrifuged, washed three times with ethanol and deionized water respectively, and the resulting gel is dried at 60°C for 6 hours. S6. Calcination: After drying, the temperature is increased to 600℃ at 5℃ / min in air atmosphere and calcined for 2h to remove the template agent and organic impurities, thereby obtaining the highly microporous nano-silica.

2. The method for preparing highly microporous nano-silica according to claim 1, characterized in that, The silicate ester is one of methyl silicate and ethyl silicate.

3. The method for preparing highly microporous nano-silica as described in claim 1, characterized in that, In step S2, the corresponding alcohols are recovered through an alcohol recovery device.

4. The method for preparing highly microporous nano-silica as described in claim 1, characterized in that, The template agent is one of P123 and hexadecyltrimethylammonium bromide (CTAB).

5. The method for preparing highly microporous nano-silica as described in claim 1, characterized in that, In step S32, while stirring for another hour, functionalized precursors are gradually added to form a functionalized silica network structure.

6. The method for preparing highly microporous nano-silica as described in claim 5, characterized in that, Using methyltriethoxysilane as the functional group precursor, the methyltriethoxysilane is gradually added during stirring to form a silica network structure with methyl functionalization.

7. The method for preparing highly microporous nano-silica as described in claim 1, characterized in that, In step S1, the anionic modifier includes at least one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium dodecylbenzene sulfonate, sodium dibutylnaphthalene sulfonate, sodium dodecyl diphenyl ether sulfonate, sodium stearate, N,N-dihydroxyethyl lauramide, and sodium isotridecyl ether sulfate.

8. The method for preparing highly microporous nano-silica as described in claim 1, characterized in that, Cooling is performed after step S6: After calcination, the mixture is allowed to cool naturally to room temperature to avoid particle agglomeration.