JP7388273B2 - Indicator materials and usage - Google Patents

Description

The present invention relates to reusable indicator materials and methods of use.

Mesoporous silica is a substance that uses silicon dioxide as a substrate and has uniform and regular pores. Mesoporous silica powder is expected to find new applications as catalysts, adsorbents, antibacterial agents, gas sensors, separation membranes, etc.

Patent Document 1 proposes mesoporous silica that has both moisture or protein adsorption and desorption properties and can be used repeatedly. Further, the present inventors have proposed porous silica doped with metal X, which is Mn or Cu, in Patent Document 2.

Japanese Patent Application Publication No. 2013-17930 Patent Application No. 2020-15640

So far, mesoporous silica materials that are removable and reusable have been proposed, but they have not yet been fully satisfactory in terms of color development and usage environment.

According to the present invention, an indicator material made of mesoporous silica with Cu or Mn introduced into siloxane bonds is provided.
Further, according to the present invention, the mesoporous silica is a mesoporous silica in which Cu or Mn is introduced into the siloxane bond, and Cu or Mn and sulfur odor are adsorbed, and the sulfur odor is caused to coexist with the active species. Provided is a method for using an indicator material that allows Cu or Mn to separate from Cu or Mn and repeatedly exhibits adsorption performance.

According to the present invention, a repeatable indicator is provided.

The greatest feature of the present invention is that it exhibits excellent color reaction. That is, the odor component enters the pores and binds to the metal almost at the same time as it enters the pores, so that a coloring reaction occurs quickly. Further, the color reaction can be visually confirmed, and the desired performance can be achieved even after repeated use.

(Mesoporous silica)
Mesoporous silica of the present invention having a specific surface area of 500 m2/g or more, preferably 800 to 2000 m2/g, particularly preferably 800 to 1600 m2/g can be suitably used.
Mesoporous silica of the present invention having pores in the range of 2 to 50 nm can be suitably used.
The specific surface area of the mesoporous silica of the present invention is preferably 500 m2/g or more.
In the mesoporous silica of the present invention, Cu is introduced into the siloxane bonds formed in the pores.
In the mesoporous silica of the present invention, a metal is introduced into the siloxane bonds of the silica pore walls. The metal content is suitably in the range of 0.01 to 10% by weight, preferably 0.1 to 5% by weight. This is because if the Cu content is less than 0.01% by mass, the desired performance cannot be fully exhibited, and if it exceeds 10% by mass, productivity and economy will be poor.

(color reaction)
The mechanism of the color reaction is thought to be that the odor component causes a reversible color change due to chemisorption and desorption. Examples of odor components include nitrogen-based odorants such as ammonia and trimethylamine, and sulfur-based odorants such as hydrogen sulfide and methyl mercaptan.
When the mesoporous silica used in this embodiment is Cu, it is usually white or light blue, but when the metal introduced into the siloxane bond of the silica pore wall is Cu, the odor substance to be adsorbed is When the odor is ammonia, the color changes to bluish, and when the odor substance being adsorbed is hydrogen sulfide, the color changes to brown.

The mesoporous structure of this embodiment shows an excellent color reaction. This is also clear from the examples described below. Example 1, in which Cu was introduced into the siloxane bond, showed a coloring reaction to odor components, whereas Comparative Example 1, in which Al was introduced, did not show any coloring reaction. Furthermore, when the sample obtained in Example 1 was chemically adsorbed with sulfur odor and then given active species, it returned to its original white color. When the deodorizing capacity after the regeneration treatment was confirmed, it was confirmed that more than 90% had been recovered.
It has been known that the performance of acidic and basic odors (hydrogen bonds caused by silanol groups) can be restored by washing with water, but even sulfur-based odors, which are strongly deodorized by chemical bonds, can be returned to their original color by ozone treatment. I knew I would be back.

A method for returning the color-reacted indicator to its original color is to use radicals such as hydroxyl radicals (・OH), superoxide, nitric oxide radicals, and oxygen radicals, or negatively-charged radicals containing at least one of these radicals. By coexisting with active species such as charged particulate water and ozone (O3), the chemical bond with the odorous substance is cut, thereby making it possible to release the odorous substance from the metal.
It is known that ozone reacts with indigo and hydrogen sulfide reacts with lead acetate, but materials that can detect these two by color are not well known.

Although the method for producing the indicator material of the present invention is not limited to the following, for example, a metal component source is dissolved in a solvent, a silica source is added, and the mixture is heated at 50 to 150° C. for 30 minutes to 12 hours. A gel-like product is obtained, and the gel-like product is further calcined at 200-550° C. for 1-10 hours.

For example, water can be used as the solvent. In addition to water, it may contain an organic solvent such as ethanol or toluene.
Examples of the silica source include tetraethoxysilane, tetramethoxysilane, tetra-n-butoxysilane, sodium silicate, and more preferably tetraethoxysilane. These silica sources may be used alone or in combination of two or more.

A surfactant solution is prepared by adding a surfactant and a metal salt to a solvent. The surfactant solution is stirred at room temperature or higher and 200° C. or lower for 30 minutes or more and 10 hours or less. This causes the surfactant to form micelles.
A silica source is then added to the surfactant solution in which micelles have been formed.

The amount of surfactant added is preferably 50 to 400 mmol/L, more preferably 50 to 150 mmol/L.
Moreover, the micelles formed by the surfactant function as a molecular template that electrostatically accumulates the silica source on the surface of the micelles. In view of this, it is preferable to add 0.01 to 5.0 mol of surfactant, more preferably 0.05 to 1.0 mol, per 1 mol of silica source.

The surfactant is not particularly limited. Any cationic, anionic, amphoteric, or nonionic surfactant may be used, but anionic or amphoteric surfactants are preferred, and alkylammonium salts are more preferred. The alkylammonium salt preferably has a carbon number of 8 or more, and in view of industrial availability, one having a carbon number of 12 to 18 is more preferred. Alkylammonium salts include hexadecyltrimethylammonium chloride, cetyltrimethylammonium bromide, stearyltrimethylammonium bromide, cetyltrimethylammonium chloride, stearyltrimethylammonium chloride, dodecyltrimethylammonium bromide, octadecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, octadecyltrimethylammonium bromide Examples include chloride, didodecyldimethylammonium bromide, ditetradecyldimethylammonium bromide, didodecyldimethylammonium chloride, ditetradecyldimethylammonium chloride, and the like. These surfactants may be used alone or in combination of two or more.

The metal component is added as a source of metal introduced into the siloxane bonds of the silica pore walls. As the metal component, water-soluble copper salts such as copper chloride, copper nitrate, and copper sulfate, or water-soluble manganese salts such as manganese chloride and manganese nitrate may be used alone or in combination of two or more. As other metal components, water-soluble metal salts such as iron chloride and aluminum chloride can be used. The amount of these metal components added is preferably 0.01 to 5.0 mol, more preferably 0.05 to 1.0 mol, per 1 mol of the silica source. It is preferable to use Al in addition to Cu in order to suppress hydrolysis of the silica skeleton.

The amount of the silica source added is preferably 0.2 to 1.8 mol/L, more preferably 0.2 to 0.9 mol/L. When the solvent contains water, it is preferable to add 0.001 to 0.05 mol of the silica source per 1 mol of water.

Since the indicator material of the present invention exhibits coloration in response to odor components, it is easy to visually confirm the indicator material. It can be used in the form of fibers, filters, detection tubes, tapes, tar labels, resin sheets, etc. It can also be used by directly attaching it to sportswear, nursing clothing, clothing, bedding, shoes, and boots. For example, the deodorizing ability can be experienced by comparing products with and without deodorizing ingredients, which can be used in sales promotions and the like. In addition, since it is a measure of surplus performance, it can be used as a measure of regeneration treatment time such as ozone treatment and indicator material replacement timing.
In addition, the indicator material of the present invention enables color detection of the concentration and amount of active species by utilizing the property of returning to the original color. The degree of color change can be measured using a sensor or image. That is, by placing an indicator in a predetermined location after a color reaction in which odor components are chemically adsorbed, it is possible to measure the concentration and amount of ozone present in a space.

This example is shown below, but the invention is not limited thereto.

(Specific surface area measurement)
A nitrogen adsorption/desorption isotherm was measured using a high-precision gas/vapor adsorption measuring device BERSORP-maxII manufactured by Microtrac Bell, Inc., and the specific surface area was calculated by the BET method.

(spectral colorimetry)
The L* value, a* value, and b* value were measured using an SM color computer (SM-4) manufactured by Suga Test Instruments Co., Ltd. The lightness was calculated using the L* value, and the saturation was calculated using √(a*2+b*2). The larger the brightness value, the whiter the color. The smaller the saturation number, the more achromatic the color.

(Measurement of metal content in mesoporous silica)
Approximately 50 mg of the sample was accurately weighed and dissolved in 4 ml of hydrochloric acid, and then the copper, manganese, and aluminum concentrations in the aqueous solution were measured using ICP-OES manufactured by Thermo Scientific. It is considered that by treatment with hydrochloric acid, all of the copper and aluminum contained in the mesoporous silica and the components incorporated into the silica skeleton are dissolved in the hydrochloric acid. Therefore, based on the measurement results, the total copper content and the total aluminum content present in mesoporous silica were calculated as "copper content" and "aluminum content", respectively.

(Hydrogen sulfide adsorption test and deodorizing capacity calculation)
A deodorant sample tube was prepared by filling a Teflon (registered trademark) tube with a diameter of 10 mm with silica wool carrying 20 mg of each deodorant. The test was started by continuously generating hydrogen sulfide at a concentration of 14 ppm using a permeator, and connecting the prepared deodorant sample tube to the hydrogen sulfide gas generation port of the permeator. After 3 minutes, 500 ml of the gas discharged from the deodorant sample tube outlet was sampled, and the hydrogen sulfide concentration was measured using a detection tube. In this measurement, the test was terminated when the hydrogen sulfide concentration became less than 7 ppm, and the deodorizing capacity mg/g per 1 g of deodorant was calculated using the test time until the hydrogen sulfide concentration became 7 ppm or more and the amount of hydrogen sulfide. .

(Ammonia adsorption test and calculation of deodorizing capacity)
A deodorant sample tube was prepared by filling a Teflon (registered trademark) tube with a diameter of 10 mm with silica wool carrying 40 mg of each deodorant. A permeator was used to continuously generate ammonia at a concentration of 100 ppm, and the test was started by connecting the prepared deodorant sample tube to the ammonia gas generation port of the permeator. After 3 minutes, 500 ml of the gas discharged from the deodorant sample tube outlet was sampled, and the hydrogen sulfide concentration was measured using a detection tube. In this measurement, the test was terminated when the ammonia concentration reached 50 ppm or more. Using the test time until the ammonia concentration reached 50 ppm or more and the amount of ammonia, the deodorizing capacity mg/g per 1 g of deodorant was calculated.

(Breakthrough treatment with hydrogen sulfide)
Continuously generate hydrogen sulfide at a concentration of 14 ppm using a permeator, and blow hydrogen sulfide at a flow rate of 1 L/min for over 48 hours into an eggplant flask filled with 0.5 g to 1 g of each deodorant to cause breakthrough. Ta. This treatment was called "hydrogen sulfide breakthrough treatment." The degree of hydrogen sulfide breakthrough treatment is determined by a hydrogen sulfide adsorption test in which the deodorizing capacity of the deodorant immediately after breakthrough is reduced by 80% or more compared to the deodorizing capacity of the deodorant before breakthrough. It was confirmed. If the amount is insufficient, the above-mentioned breakthrough treatment will be performed again.

(Breakthrough treatment with ammonia)
Ammonia with a concentration of 100 ppm was continuously generated using a permeator, and ammonia was sprayed at a flow rate of 1 L/min for over 48 hours into an eggplant flask filled with 0.5 g to 1 g of each deodorant to cause breakthrough. This treatment was referred to as "ammonia breakthrough treatment." As for the extent of ammonia breakthrough treatment, it was confirmed in an ammonia adsorption test that the deodorizing capacity of the deodorant immediately after breakthrough was reduced by more than 80% compared to the deodorizing capacity of the deodorant before breakthrough. did. If the amount is insufficient, the above-mentioned breakthrough treatment will be performed again.

(Ozone treatment and deodorizing capacity after treatment)
Spread each deodorizer untreated, after hydrogen sulfide breakthrough treatment, and after ammonia breakthrough treatment in a pre-Petri dish, and use an ozone generator (manufactured by Iwasaki Electric Co., Ltd.: OC-250615-DA). Ozone treatment was carried out by allowing 166 ppm of ozone and each deodorant to coexist for 60 minutes. A hydrogen sulfide adsorption test was conducted for each deodorant after treatment, and the "deodorization capacity after treatment with ozone" was obtained.

(Hydroxy radical treatment and deodorizing capacity after treatment)
Each deodorant untreated, after hydrogen sulfide breakthrough treatment, and after ammonia breakthrough treatment is housed in a small bag made of nonwoven fabric, and the bag containing each deodorant and a hydroxyl radical generator (manufactured by Panasonic Corporation: MS- Treatment with hydroxyl radicals was performed in coexistence with hydroxyl radicals generated from DM10-M). A hydrogen sulfide adsorption test was conducted on each deodorant after treatment, and the "deodorization capacity after treatment with hydroxyl radicals" was obtained.

(Manufacturing example 1)
Hexadecyltrimethylammonium chloride as a surfactant, copper chloride as a copper salt, and aluminum chloride as an aluminum salt were added to water as a solvent, and the mixture was stirred at 100°C for 1 hour. After the reaction solution was cooled to room temperature, tetraethoxysilane was added as a silica source to the solution in which micelles were formed, and the solution was stirred until it became homogeneous. Next, sodium hydroxide was added as a condensation catalyst so that the pH immediately after addition was 9, and the mixture was stirred at room temperature for 20 hours. The amount of each compound added was as follows per 1 mole of tetraethoxysilane.
・Hexadecyltrimethylammonium chloride: 0.225 mol ・Copper chloride: 0.0204 mol ・Aluminum chloride: 0.0482 mol ・Water: 125 mol ・Sodium hydroxide: 0.195 mol

Next, the micelles in the solution were collected as a precursor, dried at 50°C for 24 hours, and then the precursor was calcined at 570°C for 5 hours to remove organic components, thereby producing mesoporous silica (working number "TB-2"). ”) was created. The produced mesoporous silica had a specific surface area of 1100 m ² /g and a pore diameter of 2.51 nm. The specific surface area and pore diameter were determined by the BJH method from the nitrogen gas adsorption isotherm at liquid nitrogen temperature.
Table 1 shows the results of specific surface area measurement, spectrophotometry, and metal content of mesoporous silica.

(Manufacturing example 2)
Hexadecyltrimethylammonium chloride as a surfactant, manganese chloride as a manganese salt, and aluminum chloride as an aluminum salt were added to water as a solvent, and the mixture was stirred at 100°C for 1 hour. After the reaction solution was cooled to room temperature, tetraethoxysilane was added as a silica source to the solution in which micelles were formed, and the solution was stirred until it became homogeneous. Next, sodium hydroxide was added as a condensation catalyst so that the pH immediately after addition was 9, and the mixture was stirred at room temperature for 20 hours. The amount of each compound added was as follows per 1 mole of tetraethoxysilane.
・Hexadecyltrimethylammonium chloride: 0.225 mol ・Manganese chloride: 0.0102 mol ・Aluminum chloride: 0.0241 mol ・Water: 125 mol ・Sodium hydroxide: 0.195 mol Next, the micelles in the solution are converted into precursors. After drying at 50° C. for 24 hours, the precursor was calcined at 570° C. for 5 hours to remove organic components, thereby producing mesoporous silica (execution number “CB-16”).
(Manufacturing example 3)
Hexadecyltrimethylammonium chloride as a surfactant and aluminum chloride as an aluminum salt were added to water as a solvent, and the mixture was stirred at 100°C for 1 hour. After the reaction solution was cooled to room temperature, tetraethoxysilane was added as a silica source to the solution in which micelles were formed, and the solution was stirred until it became homogeneous. Next, sodium hydroxide was added as a condensation catalyst so that the pH immediately after addition was 9, and the mixture was stirred at room temperature for 20 hours. The amount of each compound added was as follows per 1 mole of tetraethoxysilane.
・Hexadecyltrimethylammonium chloride: 0.225 mol ・Aluminum chloride: 0.0482 mol ・Water: 125 mol ・Sodium hydroxide: 0.195 mol

Next, the micelles in the solution were collected as a precursor, dried at 50°C for 24 hours, and then the precursor was calcined at 570°C for 5 hours to remove organic components, thereby producing mesoporous silica (implementation number "TCB-1"). ”) was created.

(Example 1) Ozone treatment Using the mesoporous silica "TB-2" obtained in Production Example 1, an adsorption test with hydrogen sulfide was conducted to obtain "initial deodorizing capacity". Next, a breakthrough treatment with hydrogen sulfide was carried out, and the extent of the breakthrough treatment was confirmed by an adsorption test. Furthermore, after ozone treatment, an adsorption test with hydrogen sulfide was conducted to obtain the "deodorizing capacity after regeneration treatment." The results are shown in Table 2.
In addition, spectroscopic colorimetry was performed after the breakthrough treatment and after the ozone treatment to confirm color changes. The results are shown in Table 3.

(Example 2) Hydroxy radical treatment Using the mesoporous silica "TB-2" obtained in Production Example 1, an adsorption test with hydrogen sulfide was conducted to obtain "initial deodorizing capacity". Next, a breakthrough treatment with hydrogen sulfide was carried out, and the extent of the breakthrough treatment was confirmed by an adsorption test. Furthermore, after hydroxyl radical treatment, an adsorption test with hydrogen sulfide was conducted to obtain the "deodorizing capacity after regeneration treatment." The results are shown in Table 2.
In addition, spectroscopic colorimetry was performed after the breakthrough treatment and after the hydroxyl radical treatment to confirm color changes. The results are shown in Table 3.

(Example 3) Repeated treatment twice Using the mesoporous silica "TB-2" obtained in Production Example 1, breakthrough treatment with hydrogen sulfide and ozone treatment were repeated twice. After the two-time repeated treatment, an adsorption test with hydrogen sulfide was conducted to obtain the "deodorizing capacity after the two-time repeated regeneration treatment." The results are shown in Table 2.
In addition, spectroscopic colorimetry was performed after the breakthrough treatment and after the regeneration treatment repeated twice to confirm color changes. The results are shown in Table 3.

(Example 4) Manganese Using the mesoporous silica "CB-16" obtained in Production Example 2, an adsorption test with hydrogen sulfide was conducted to obtain "initial deodorizing capacity". Next, a breakthrough treatment with hydrogen sulfide was carried out, and the extent of the breakthrough treatment was confirmed by an adsorption test. Furthermore, after ozone treatment, an adsorption test with hydrogen sulfide was conducted to obtain the "deodorizing capacity after regeneration treatment." The results are shown in Table 2.
In addition, spectroscopic colorimetry was performed after the breakthrough treatment and after the ozone treatment to confirm color changes. The results are shown in Table 3.

(Reference Example 1) Ozone treatment without breakthrough treatment Using the mesoporous silica "TB-2" obtained in Production Example 1, an adsorption test with hydrogen sulfide was conducted to obtain "initial deodorizing capacity". Next, ozone treatment was performed without decomposition treatment with hydrogen sulfide, and then an adsorption test with hydrogen sulfide was conducted to obtain the "deodorizing capacity after regeneration treatment." The results are shown in Table 2.
In addition, spectroscopic colorimetry was performed after ozone treatment to confirm color changes. The results are shown in Table 3.

(Comparative Example 1) Water Washing Treatment Using the mesoporous silica "TB-2" obtained in Production Example 1, an adsorption test with hydrogen sulfide was conducted to obtain "initial deodorizing capacity". Next, a breakthrough treatment with hydrogen sulfide was carried out, and the extent of the breakthrough treatment was confirmed by an adsorption test. Furthermore, the mesoporous silica after the breakthrough treatment was adjusted with water to 0.1% by weight, stirred with a magnetic stirrer at 300 rpm for 2 hours, washed with water, and the mesoporous silica was recovered by suction filtration. Drying was performed at 65°C for 2 hours. Using mesoporous silica washed with water, an adsorption test with hydrogen sulfide was conducted to obtain the "deodorizing capacity after regeneration treatment." The results are shown in Table 2.
In addition, spectroscopic colorimetry was performed after the breakthrough treatment and after the ozone treatment to confirm color changes. The results are shown in Table 3.

(Example 5) Ozone treatment It was carried out in the same manner as in Example 1 except that the odor was changed to ammonia. The results are shown in Tables 4 and 5.

(Example 6) Hydroxy radical treatment It was carried out in the same manner as in Example 2 except that the odor was changed to ammonia. The results are shown in Tables 4 and 5.

(Example 7) Repeated treatment twice Using the mesoporous silica "TB-2" obtained in Production Example 1, breakthrough treatment with ammonia and ozone treatment were repeated twice. After the repeated treatment twice, an adsorption test with ammonia was conducted, and the "deodorizing capacity after the repeated regeneration treatment twice" was obtained. The results are shown in Tables 4 and 5.

(Reference Example 2) Ozone treatment without breakthrough treatment It was carried out in the same manner as Reference Example 1 except that the odor was changed to ammonia. The results are shown in Tables 4 and 5.

(Comparative Example 2) Water washing treatment The same procedure as Comparative Example 1 was carried out except that the odor was changed to ammonia. The results are shown in Tables 4 and 5.

(Comparative Example 3) Ozone treatment of aluminum-doped mesoporous silica Ozone treatment was carried out in the same manner as in Example 4 except that the mesoporous silica "TCB-1" obtained in Production Example 3 was used. The results are shown in Tables 4 and 5.

As is clear from Tables 2 and 3, in the deodorant made of mesoporous silica in which copper is introduced as a metal atom into the siloxane bonds of the silica pore walls, chemical adsorption of hydrogen sulfide and copper is saturated, so-called After reaching the breakthrough point, it became possible to recover and regenerate the initial deodorizing capacity by performing ozone treatment or treatment with hydroxyl radicals. Compared to the conventional treatment using water washing in Comparative Example 1, the recovery performance was significantly improved.

The present invention achieves deodorizing speed through chemical adsorption, while at the same time improving the deodorizing life, which was an issue with chemical adsorption, by allowing the deodorizer to coexist with active species from ozone treatment, etc., thereby improving deodorizing performance repeatedly. We have found that this can be expressed.

Furthermore, the deodorant changed color from light blue to brown due to chemical adsorption with hydrogen sulfide. Thereafter, by performing ozone treatment or hydroxyl radical treatment, the color changed from brown to light blue or light green. In the present invention, it has been found that reaching the breakthrough point of deodorization and progress of regeneration treatment can be visually confirmed by the change in color of the deodorant.

As is clear from Tables 4 and 5, it is possible to repeatedly develop deodorizing performance for ammonia by coexisting with active species such as deodorizers and ozone treatment, and to reach the breakthrough point of deodorization. It has been found that the arrival of deodorant and the progress of the regeneration process can be visually confirmed by the change in color of the deodorant. Further, since there are metal atoms that exhibit a coloring reaction and metal atoms that do not, it is possible to appropriately select one as required.

(Comparative example 4)
Mesoporous silica MCM-41 (CAS RN: 7631-86-9) manufactured by Sigma-Aldrich was prepared as Comparative Example 4. The specific surface area of this powder sample was 894 m ² /g, and the pore diameter was 2.61 nm. The specific surface area and pore diameter were determined by the BJH method from the nitrogen gas adsorption isotherm at liquid nitrogen temperature.

(Deodorizing speed)
Two 500 mL Erlenmeyer flasks were prepared, and a permeator was used in each Erlenmeyer flask to prepare hydrogen sulfide gas to an initial concentration of 19 ppm. 10 mg of mesoporous silica of Example 1 and Comparative Example 4 were added to separate Erlenmeyer flasks. The amount of hydrogen sulfide in the Erlenmeyer flask after 5 minutes was measured using a gas detection tube (manufactured by Gastech).
The results are shown in the table below.

Example 1 has a faster deodorizing speed than Comparative Example 4. Since there is no significant difference in specific surface area and pore diameter between Example 1 and Comparative Example 4, it is considered that the fast deodorization rate of the powder in Example 1 is due to the effect of the metal dope.

Claims (6)

An indicator material made of mesoporous silica with Cu or Mn introduced into siloxane bonds. 2. The indicator material of claim 1, wherein the indicator material exhibits a coloration upon reaction with an odor. 3. The indicator material according to claim 1, wherein the mesoporous silica is chemically bound to a sulfur odor, and the ozone concentration or amount is measured by a color reaction of the indicator. 3. The indicator material according to claim 1, wherein the mesoporous silica is chemically bonded with a sulfur odor, and the sulfur odor concentration is measured by a color reaction of the indicator. Mesoporous silica with Cu or Mn introduced into the siloxane bond. Cu or Mn and sulfur odor are adsorbed, and by allowing the sulfur odor and active species to coexist, the sulfur odor is released from Cu and adsorbed repeatedly. How to use indicator materials to develop performance. The method according to claim 5, wherein after the mesoporous silica reacts with a sulfur-based odor and exhibits coloration, the color is measured while the mesoporous silica and active species coexist, and the active species treatment is terminated based on the measurement result. How to use indicator materials.