JP6774615B2 - Porous silica and deodorants containing it - Google Patents

Description

The present invention relates to porous silica, a deodorant containing the same, and a method for producing porous silica. More specifically, it has a large specific surface area because it is composed of particles having primary pores derived from the template and has secondary pores consisting of particle gaps due to the binding of the particles to each other, and the introduced fatty acid metal. It relates to porous silica carrying a metal-containing substance derived from a salt.

Many studies have been reported on metal-containing porous silica. For example, in "J. Ceram. Soc. Japan, 109, [10], 818-822 (2001)" by Li Xian, Masato Uehara, Naoya Enomoto, Junichi Hojo, etc.
(1) By dropping tetraethoxysilane and tetraethoxytitanium into a polyoxyethylene [23] lauryl ether aqueous solution to which hydrochloric acid is added, a porous body containing silica and titanium is formed, and (2) mesoporous silica. It is described that a porous body containing zinc oxide is produced by mixing the mixture with zinc nitrate and then firing the mixture.
Further, Japanese Patent Application Laid-Open No. 4-313348 describes a method for producing a catalyst for supporting a metal or a metal oxide by immersing a carrier in an organic solution of an organic metal compound and supporting the organic compound on the carrier. ..
Further, Japanese Patent Application Laid-Open No. 2002-187712 states that a mixture containing a water-miscible organic solvent, an alkylamine and a silicic acid ester, or a combination of a silicic acid ester and a metal salt soluble in a water-miscible organic solvent is stirred. Spherical porous silica and silica metal composite particles characterized by adding water or an acidic aqueous solution underneath to grow the resulting silica-alkylamine composite product into spherical particles and removing the alkylamine in the spherical particles. The manufacturing method of is described.

Japanese Unexamined Patent Publication No. 4-313348 JP-A-2002-187712

Xianying Li et al., J. Ceram. Soc. Japan, 109, [10], 818-822 (2001)

When a metal component other than Si is introduced during the synthesis (Japanese Patent Laid-Open No. 2002-187712), a metal alkoxide or a direct metal alkoxide or a direct substance is used in order to form a stable homogeneous solution phase with the silicate ester tetraethyl altosilicate (TEOS). There is a problem that only limited metal salts soluble in chain alkylamines and water can be used. The metal alkoxide is expensive, and it is necessary to adjust the hydrolysis and condensation reaction rates with the silica source, which makes it difficult to control the reaction.
It is known that odors such as ammonia, acetic acid, and acetaldehyde are chemically adsorbed by silanol groups on the surface of silica, but since the number of silanol groups per unit area is almost constant, the deodorizing power per unit weight is increased. In order to improve it, it is necessary to increase the specific surface area.
When a metal component is introduced into the synthesized porous body by post-treatment (Japanese Patent Laid-Open No. 4-313348), the metal is supported in the already completed pores, so that the specific surface area and pore volume , There is a problem that the pore size becomes a small porous body.

The present invention is a porous silica containing particles in which primary pores are formed, wherein the particles contain a metal-containing substance having a particle size of 1 to 100 nm and a specific surface area of 500 m ² / g or more. Provided is porous silica.
The present invention also provides a deodorant containing the porous silica.
Further, in the present invention, the silica source is accumulated on the surface of the micelle structure in which the fatty acid metal salt, the surfactant and the silica source are added to the aqueous solution and the fatty acid metal salt and the surfactant are mixed.
A basic aqueous solution was added to the dispersion to form a precursor, and in the precursor, a silica wall was formed, and the fatty acid metal salt was localized inside the silica wall.
The precursor is filtered, dried and
Provided is a method for producing porous silica containing a metal-containing substance derived from the fatty acid metal salt produced by firing the precursor to remove the surfactant in the micelle structure.

The porous silica of the present invention can effectively deodorize odors such as methyl mercaptan, hydrogen sulfide, and nonenal, which are difficult to deodorize with a metal-free silica porous body. Further, the porous silica of the present invention has a high specific surface area and has many silanol groups on the silica surface, and also has a complicated pore structure composed of primary pores and secondary pores. Odors known to be chemically adsorbed on the surface of silica such as ammonia, trimethylamine, acetic acid, and isovaleric acid also show a large deodorizing rate and deodorizing capacity.

The TEM image of the cross section of Example 2 is shown. The TEM image of the cross section of Example 4 is shown. The measurement result of the particle size distribution is shown.

The porous silica of the present invention is a porous silica containing particles in which primary pores are formed.
The primary pores of the particles are formed by arranging the silica sources in an aqueous solution using a fatty acid metal salt and a surfactant as templates. The primary pores are generally considered to have a pore diameter of 1 to 20 nm.
The surfactant is preferably neutral, cationic, and more preferably an alkylammonium salt. The alkylammonium salt may have 8 or more carbon atoms, but is more preferably 12 to 18 carbon atoms in view of industrial availability. As alkylammonium salts, cetyltrimethylammonium bromide, stearyltrimethylammonium bromide, cetyltrimethylammonium chloride, stearyltrimethylammonium chloride, dodecyltrimethylammonium bromide, octadecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, didodecyldimethylammonium. Examples thereof include bromide, ditetradecyldimethylammonium bromide, didodecyldimethylammonium chloride, and ditetradecyldimethylammonium chloride. These surfactants may be used alone or in combination of two or more. The concentration of the surfactant in the aqueous solution is preferably 50 to 400 mmol / L, more preferably 50 to 150 mmol / L. Surfactants function as molecular templates that form micelles in water and electrostatically accumulate silica sources on their surfaces. The surfactant disappears by firing to form primary pores.

The fatty acid metal salt is preferably a fatty acid metal salt having 8 to 18 carbon atoms, and more preferably a fatty acid metal salt having 12 to 18 carbon atoms. Examples of the fatty acid metal salt include, but are not limited to, octanate, laurate, and stearate. Examples of the metal of the fatty acid metal salt include zinc, silver, nickel, copper, cobalt, manganese, cerium, and zirconium. The metal is preferably zinc, silver, copper, manganese and cobalt. These fatty acid metal salts may be used alone or in combination of two or more. The concentration of the fatty acid metal salt in the aqueous solution is preferably lower than the concentration of the surfactant, more preferably 0.2 to 5 mmol / L. Since the fatty acid metal salt is insoluble in water, it is preferentially solubilized inside the micelle, which is a hydrophobic environment. Therefore, the metal can be localized inside the micelle, and nanoparticles of the metal-containing substance can be supported inside the pores.

The silica source is preferably alkoxysilane. The organic functional groups on the silicon atom are lost by hydrolysis and do not affect the structure of the compound. However, if the organic functional group is bulky, the hydrolysis rate will be slow and the synthesis time will be long. Therefore, tetraethoxysilane, tetramethoxysilane, tetra-n-butoxysilane, sodium silicate and the like are preferable. The silica source is more preferably tetraethoxysilane. These silica sources may be used alone or in combination of two or more. The concentration of the silica source in the aqueous solution is preferably 0.2 to 1.8 mol / L, more preferably 0.2 to 0.9 mol / L. When sodium silicate is used alone or in combination as the silica source, the operation of heating and refluxing in an aqueous solution at 200 ° C. or lower for 20 to 2 hours is performed. The silica source is hydrolyzed (accelerated with acidity or neutrality) and then connected by a dehydration condensation reaction (accelerated with basicity) to form a silica wall.

In the porous silica of the present invention, the particles contain a metal-containing substance having a particle size of 1 to 100 nm. The particle size can be adjusted by controlling the concentration of the fatty acid metal salt in the aqueous solution and the carbon chain of the fatty acid.
Further, in the porous silica of the present invention, the specific surface area is 500 m ² / g or more. The specific surface area is preferably 1000 m ² / g or more, and more preferably 1200 m ² / g or more. It is known that odors such as ammonia, acetic acid, and acetaldehyde are chemically adsorbed by silanol groups on the surface of silica, but since the number of silanol groups per unit area is almost constant, the deodorizing power per unit weight is improved. For that purpose, it is necessary to increase the specific surface area.
The porous silica of the present invention preferably has secondary pores formed by particle spacing due to bonding between the particles. This is because the presence of the coarse secondary pores can be expected to have the effect of rapidly diffusing the gas to the primary pores existing inside, which leads to an increase in the deodorizing capacity and the deodorizing rate.

The porous silica of the present invention can be used by mixing with a resin. Since the porous silica of the present invention is formed from silica and a metal-containing substance, it has high heat resistance. As the resin, any conventionally known thermoplastic resin that can be melt-molded can be used. For example, low-, medium-, or high-density polyethylene, linear low-density polyethylene, linear ultra-low density polyethylene can be used. , Isotactic polypropylene, Syndiotactic polypropylene, propylene-ethylene copolymer, polybutene-1, ethylene-butene-1 copolymer, propylene-butene-1 copolymer, ethylene-propylene-butene-1 copolymer Olefin resins such as polyethylene terephthalate, polybutylene terephthalate, polyester resins such as polyethylene naphthalate; polyamide resins such as nylon 6, nylon 6, 6 and nylon 6, 10; polycarbonate resins and the like can be mentioned. As the resin, it is particularly preferable to use polyethylene, polypropylene, or polyester.
The porous silica of the present invention preferably has a brightness L * of 80 or more. When the lightness is high, it is possible to reduce the coloring when the porous silica is kneaded with a resin or the like, and it is possible to color the desired color by mixing the pigment. If the lightness of the porous silica is low and coloring is a concern, coloring can be suppressed by reducing the amount of metal.

The deodorant of the present invention contains the porous silica. The porous silica and the porous inorganic oxide may be mixed and used. Examples of the porous inorganic oxide include zeolite, silica gel, alumina, sepiolite, spherical silica, pearlite, activated carbon (mineral-based activated carbon, etc.) which are aluminum and / or silicon oxides. The zeolite may be a synthetic zeolite or a natural zeolite (such as hojasite). The porous inorganic oxide preferably has a heat resistance of 350 ° C. or higher of the porous silica and has a heat resistance in the same temperature range so as not to impair the excellent heat resistance of the porous silica.
It is inferred that the deodorant of the present invention exhibits excellent performance as follows.
In the porous silica of the present invention, the silanol groups on the surface of the pores and the metal-containing substance supported inside the primary pores serve as deodorant sites that do not interfere with each other. By using a micellar structure consisting of a fatty acid metal salt and a surfactant to form a precursor, the fatty acid metal salt is localized inside the silica wall. By firing this, a metal-containing substance can be easily introduced into the primary pores. Basic, acidic, and aldehyde-based odorous components are adsorbed on silanol groups on the surface of porous silica, and molecules (odorous components) adsorbed by capillary condensation are trapped in the primary pores. Further, the aldehyde-based odor component undergoes an oxidative decomposition reaction due to the metal-containing substance existing inside. By such a deodorizing mechanism, the present invention presents a method of impregnating a porous silica described later with a metal solution (Comparative Example 2) and a method of firing a precursor obtained by using a metal salt soluble in water (Comparative Example 2). Compared with the deodorant obtained in Comparative Example 3), the deodorant property of the mixed odor (Tables 2 and 3) or the repetitive deodorant property (Table 4) is excellent.

In the method for producing porous silica of the present invention, a fatty acid metal salt, a surfactant, and a silica source are added to an aqueous solution, and the silica source is accumulated on the surface of a micellar structure in which the fatty acid metal salt and the surfactant are mixed. Includes steps. For example, the fatty acid metal salt and the surfactant are mixed by stirring and mixing the fatty acid metal salt and the surfactant at room temperature or more and 100 ° C. or less for 1 hour or more and 24 hours or less, and then the silica source is added to bring the fatty acid metal salt and the surfactant together. The mixed micelle and the silica source are dispersed. Further, by stirring at room temperature for 30 minutes or more, a dispersion liquid in which the silica source is accumulated on the surface of the mixed micelle can be obtained. The aqueous solution may contain an organic solvent such as ethanol or toluene in addition to water.

The method for producing porous silica of the present invention further includes a step of adding a basic aqueous solution to the dispersion to form a precursor. In the precursor, a silica wall is formed, and the fatty acid metal salt is localized inside the silica wall.
Examples of the basic aqueous solution include aqueous solutions of sodium hydroxide, sodium carbonate, ammonia and the like. The basic aqueous solution is preferably a sodium hydroxide aqueous solution. These basic aqueous solutions may be used alone or in combination of two or more. The basic aqueous solution is added so that the pH of the dispersion is preferably 8 to 14, and more preferably 9 to 11. The base accelerates the dehydration condensation reaction of the silica source. By rapidly making the solution basic while the silica source is sufficiently hydrolyzed, the dehydration condensation reaction is triggered at once. As a result, the surface tension of the condensed portion increases, the silica wall becomes spherical, and the spheres are joined in multiple layers, causing spinodal decomposition (phase separation). Chemical cross-linking freezes these structures to form secondary pores.

The method for producing porous silica of the present invention further comprises a step of filtering and drying the precursor. The precursor is filtered by suction filtration, for example, and is repeated until the pH of the filtrate reaches 7. The precursor is dried, for example, in a dryer or a vacuum dryer, and is sufficiently dried.
The method for producing porous silica of the present invention further comprises a step of calcining the precursor to remove the fatty acid and the surfactant in the micellar structure. The precursor is fired at a temperature equal to or higher than the decomposition temperature of the surfactant, preferably 500 to 600 ° C.

Since the fatty acid metal is considered to be carried in a state of being encapsulated inside the micelle of the surfactant, when the surfactant is eliminated by firing, the metal-containing substance is preferentially distributed on the pore surface of the silica porous body. It is thought that. As a result, the introduced metal-containing substance can be expected to act effectively, and can be used not only for deodorant applications but also for other industrial applications such as catalysts, separators, and adsorbents. In addition, since the metal-containing substance is encapsulated in the pores, the original color of the metal-containing substance is covered with the white color of silica, and the decrease in brightness that is generally caused when a colored metal is introduced can be suppressed. Excellent appearance of deodorant.
Since the porous silica of the present invention is not spherical, it is difficult for the surface of the pores to be uniformly covered with the resin when kneaded with the resin. This is because the presence of non-uniform particle gaps makes it difficult for the resin to penetrate into the interior due to the maze effect. Therefore, in the resin molded product kneaded with the porous silica of the present invention, the diffusion rate of the odor to the deodorant is easily maintained, and it can be expected that the effect as the deodorant is maintained even after the resin kneading.

(Test method)
(Specific surface area)
It was measured at liquid nitrogen temperature by a one-point method using Flowsorb II2300 manufactured by Micromeritix.
(color)
The brightness L * value was measured using an SM color computer (SM-4) manufactured by Suga Test Instruments Co., Ltd.
(Metal content)
After accurately weighing 50 mg of the sample and dissolving it in 5 ml of hydrochloric acid or nitric acid, the metal concentration in the aqueous solution was measured by ICP-OES manufactured by Thermo Scientific.
(Various odor deodorant tests)
500 ml of various odors were prepared. The initial concentrations were ammonia 100 ppm, pyridine 12 ppm, trimethylamine 28 ppm, acetic acid 30 ppm, isovaleric acid 38 ppm, methyl mercaptan 8 ppm, hydrogen sulfide 4 ppm, and acetaldehyde 14 ppm. After 50 mg of the sample was put therein and stirred for 30 minutes, the concentrations of various gases were measured using a gas detector tube manufactured by Gastec, and the deodorizing rate was calculated by comparing with the initial concentrations.
(High concentration acetaldehyde deodorant test)
Acetaldehyde with an initial concentration of 625 ppm was prepared in a 500 ml Erlenmeyer flask. After adding 100 mg of a sample and stirring the sample, the acetaldehyde concentration after 24 hours was measured using a gas detector tube manufactured by Gastec, and the deodorization rate was calculated by comparison with the initial concentration.
(Repeated deodorant test of acetaldehyde)
A 500 ml Erlenmeyer flask containing 100 mg of a sample was prepared. The concentration of acetaldehyde in the flask was adjusted to 700 ppm (operation 1). The residual acetaldehyde concentration after 24 hours was measured using a gas detector tube manufactured by Gastec (operation 2), and this was ventilated for 1 hour (operation 3). Operations 1 to 3 were repeated 5 times.
(TEM)
After embedding in Quetol 812 (epoxy resin), it was ultra-thin sliced with an ultramicrotome, subjected to carbon vacuum deposition, and measured at 200 kV using JEM2010 manufactured by JOEL.
(Measurement of particle size distribution)
A Zeta Sizar Nano ZS manufactured by Malvern Instruments Ltd was used for the measurement. The RI of the dispersion medium (water) is 1.330, the RI of the sample is 1.59, the viscosity is 0.8872, the absorption rate of the sample is 0.010, the temperature is set to 25 ° C., and a polystyrene disposable cell is used. Was measured. The composition of the solution was (A) hexadecyl ammonium chloride: water: sodium hydroxide = 0.225: 125: 0.225, (B) hexadecyl ammonium chloride: cobalt stearate: water: sodium hydroxide = 0.225. : 0.0106: 125: 0.225, (C) Tetraethoxysilane: Hexadecylammonium chloride: Cobalt stearate: Water: Sodium hydroxide = 1: 0.225: 0.0106: 125: 0.225 ..

(Example 1)
Water, dodecyltrimethylammonium chloride and zinc stearate were added to a 300 ml beaker, and the mixture was stirred at 100 ° C. for 1 hour to prepare an aqueous solution in which zinc stearate was uniformly dispersed. After cooling to room temperature, tetraethoxysilane was added and stirred until homogeneous. Then, an aqueous sodium hydroxide solution was added, and the stirrer was rotated at 1000 rpm to stir for 20 hours. The molar ratio of the mixed solution was such that the amount of Zn in the compound was 1 wt%, tetraethoxysilane: dodecyltrimethylammonium chloride: zinc stearate: water: sodium hydroxide = 1: 0.225: 0.0094: 125: 0.196. The solid product was filtered off from the obtained suspension, vacuum dried at 80 ° C., and then heated at 570 ° C. for 5 hours to remove organic components. The evaluation results of the composites are shown in Table 1. Table 2 shows the results of various odor deodorant tests.

(Example 2)
A compound was obtained in the same manner as in Example 1 except that hexadecyltrimethylammonium chloride was used in place of dodecyltrimethylammonium chloride and manganese stearate was used in place of zinc stearate. The molar ratio of the mixed solution was such that the amount of Mn in the compound was 1 wt%, tetraethoxysilane: hexadecyltrimethylammonium chloride: manganese stearate: water: sodium hydroxide = 1: 0.225: 0.0111. : 125: 0.225. The evaluation results of the composites are shown in Table 1. Table 2 shows the deodorizing performance of methyl mercaptan. A TEM image of the cross section is shown in FIG. It has a structure in which particles having uniform primary pores (white dots) of 1 to 20 nm are aggregated. In addition, it has secondary pores (epoxy resin looks white (for example, circled parts)) formed by particle gaps, and contains particles (black parts) of a metal-containing substance having a diameter of 1 to 100 nm. On the surface of the obtained composite, particles of a metal-containing substance having a diameter of 1 to 100 nm as seen in the TEM image of the cross section were not observed.

(Example 3)
A compound was obtained in the same manner as in Example 1 except that silver stearate was used instead of zinc stearate. The molar ratio of the mixed solution was such that the amount of Ag in the compound was 1 wt%, tetraethoxysilane: dodecyltrimethylammonium chloride: silver stearate: water: sodium hydroxide = 1: 0.209: 0.0057: 125: 0.225. The evaluation results of the composites are shown in Table 1. Table 2 shows the deodorizing performance of methyl mercaptan.

(Example 4)
A compound was obtained in the same manner as in Example 1 except that hexadecyltrimethylammonium chloride was used in place of dodecyltrimethylammonium chloride and cobalt stearate was used in place of zinc stearate. The molar ratio of the mixed solution was such that Co in the composition was 1 wt%, tetraethoxysilane: hexadecyltrimethylammonium chloride: cobalt stearate: water: sodium hydroxide = 1: 0.225: 0.0106 :. 125: 0.225. The evaluation results of the composites are shown in Table 1. Table 3 shows the deodorizing performance of high-concentration acetaldehyde, and Table 4 shows the repeated deodorizing performance of acetaldehyde. A TEM image of the cross section is shown in FIG. A structure similar to that in FIG. 1 can be confirmed in FIG. In addition, FIG. 3 shows the measurement results of the particle size distribution at each stage of synthesis. The horizontal axis is the particle size of micelles, and the vertical axis is the scattering intensity. That is, FIG. 3 shows an approximate existence probability. It was confirmed that the particle size gradually increased when the fatty acid metal salt (B) and the alkoxysilane (C) were added as compared with the case of using only the surfactant (A). From this, it was confirmed that micelles in which fatty acid metals were solubilized and accumulation of silica sources were confirmed.

(Example 5)
A compound was obtained in the same manner as in Example 4 except that cobalt octanate was used instead of cobalt stearate. The evaluation results of the composites are shown in Table 1. Table 3 shows the deodorizing performance of high-concentration acetaldehyde.

(Example 6)
Water, hexadecyltrimethylammonium chloride and copper stearate were added to a 200 ml beaker, and the mixture was stirred at 100 ° C. for 2 hours to prepare an aqueous solution in which copper stearate was uniformly dispersed. Sodium silicate was added over 20 minutes and then heated to reflux at 200 ° C. for 30 minutes. After cooling to room temperature, tetraethoxysilane was added and stirred until homogeneous. Then, an aqueous sodium hydroxide solution was added, and the stirrer was rotated at 1000 rpm to stir for 20 hours. The molar ratio of the mixed solution was such that the amount of Cu in the compound was 0.1 wt%, that is, tetraethoxysilane: sodium silicate: hexadecyltrimethylammonium chloride: copper stearate: water: sodium hydroxide = 1: 0. It was set to 0.011: 0.225: 0.0009: 125: 0.196. The solid product was filtered off from the obtained suspension, vacuum dried at 80 ° C., and then heated at 570 ° C. for 5 hours to remove organic components. The evaluation results of the composites are shown in Table 1. Table 2 shows the results of various odor deodorant tests.

(Comparative Example 1)
It was synthesized by the same method as in Example 1 except that zinc stearate was not added. The molar ratio of the mixed solution was tetraethoxysilane: dodecyltrimethylammonium chloride: water: sodium hydroxide = 1: 0.225: 125: 0.215. The evaluation results of the composites are shown in Table 1. Table 2 shows the results of various odor deodorant tests.

(Comparative Example 2)
5 ml of an 83 mmol / L cobalt nitrate aqueous solution was prepared in a 100 ml beaker, 0.9 g of commercially available mesoporous silica (MSU-F manufactured by Aldrich) was added, vacuum dried at 100 ° C., and calcined at 350 ° C. for 6 hours. The evaluation results of the composites are shown in Table 1. Table 3 shows the deodorizing performance of acetaldehyde.

(Comparative Example 3)
It was synthesized based on Japanese Patent No. 4614196. Tetraethoxysilane was added to a 200 ml beaker, the stirrer was rotated at 600 rpm to stir, and cobalt chloride dissolved in ethanol was added. Then, octylamine was added and the mixture was stirred for 10 minutes, then an aqueous hydrochloric acid solution was added, and the mixture was further stirred for 1 hour. The molar ratio of the mixed solution was tetraethoxysilane: octylamine: ethanol: cobalt chloride: hydrochloric acid: water = 1: 0.34: 1.18: 0.0105: 0.034: 38. The solid product was filtered off from the obtained suspension, vacuum dried at 100 ° C., and then heated at 600 ° C. for 1 hour to remove organic components. The evaluation results of the composites are shown in Table 1. Table 4 shows the repeated deodorizing performance of acetaldehyde.

(Comparative Example 4)
A commercially available powder deodorant (KD411G manufactured by Rasa Industries, Ltd.) was evaluated. The evaluation results are shown in Table 1. Table 4 shows the repeated deodorizing performance of acetaldehyde.

Table 1

Table 2

Table 3

Table 4

Claims (6)

Porous silica containing particles in which primary pores are formed, wherein the particles in which the primary pores are formed contain a metal-containing substance having a particle size of 1 to 100 nm and a specific surface area of 500 m ² / g. As described above, the metal-containing substance is localized and distributed on the inner surface of the primary pores, the particles of the metal-containing substance are included, the metal content is 0.08 wt% or more, and the metal is Porous silica, which is one or more selected from the group consisting of zinc, copper, manganese, and cobalt. The porous silica according to claim 1, which has secondary pores composed of particle intervals formed by bonding particles in which the primary pores are formed. The porous silica according to claim 1 or 2, wherein the lightness L * is 80 or more. The porous silica according to any one of claims 1 to 3, wherein the pore diameter of the primary pores is 1 to 20 nm. The deodorant containing the porous silica according to any one of claims 1 to 4. The fatty acid metal salt, the surfactant, and the silica source are added to the aqueous solution, and the silica source is accumulated on the surface of the micellar structure in which the fatty acid metal salt and the surfactant are mixed.
A basic aqueous solution was added to the dispersion to form a precursor, and in the precursor, a silica wall was formed, and the fatty acid metal salt was localized inside the silica wall.
The precursor is filtered, dried and
A method for producing porous silica containing a metal-containing substance derived from the fatty acid metal salt produced by calcining the precursor to remove the surfactant in the micellar structure.