KR20210119749A - Absorbent with oxygen vacancy for removing formaldehyde, A method of manufacturing the same and Absorption coating solution, Non-woven filter using the same - Google Patents

Abstract

The present invention relates to an oxygen vacancy adsorbent comprising a calcined product obtained by calcining manganese dioxide to which calcined glucose is bound and relates to an oxygen vacancy adsorbent in which glucose performs a role of nano carbon to improve adsorption capacity, and an oxygen vacancy structure performs a role of activating an oxidation reaction of formaldehyde to show excellent formaldehyde removal rate. Also, the manufacturing cost is low, and thus economic feasibility is excellent. The present invention also relates to a method of manufacturing the adsorbent, a formaldehyde adsorption coating solution comprising the same, and a nonwoven filter.

Description

Oxygen vacancy adsorbent for removing formaldehyde, manufacturing method thereof, and formaldehyde adsorption coating solution comprising same, non-woven filter

The present invention relates to an adsorbent composed of a calcined product obtained by calcining manganese dioxide bound with glucose, an oxygen vacancy adsorbent with high removal efficiency of gaseous pollutants such as formaldehyde, a method for manufacturing the same, a formaldehyde adsorption coating solution to which the same is applied, and a nonwoven filter it's about

Recently, due to the high concentration of fine dust, indoor air purification is attracting attention. Accordingly, an air purifier capable of purifying air indoors has been developed, and research is being conducted to increase the removal rate. The conventionally developed air purifier is effective in removing particulate pollutants such as fine dust, but the removal efficiency of gaseous pollutants such as formaldehyde and volatile organic compounds (VOCs) is low, so research on this is required.

Among the gaseous pollutants, formaldehyde is known as a respiratory disease and carcinogen in indoor air quality, and is known as a causative agent of sick house syndrome. To remove this, various synthetic adsorbents have been developed. Synthetic adsorbents refer to polymers or spherical particles prepared by combining two or more porous structures. Synthetic adsorbents have the advantage of being able to easily remove compounds and being able to use them longer than activated carbon, but they have the disadvantage of being expensive. For example, according to Japanese Patent No. 5212992, an aluminum silicate composite was manufactured and used as an adsorbent, but there was a problem in that the cost was relatively high.

On the other hand, _{it has been reported that metal oxides such as manganese dioxide (MnO 2} ) are regenerated by desorption of residues when they come into contact with oxygen in the atmosphere, so they are suitable as materials for synthetic adsorbents.

Japanese registered patent 5212992 (registration number: 2013.03.08)

The present invention has been proposed to solve the above problems, and it not only shows a very high removal rate for removing gaseous pollutants, but also has good economic feasibility due to low manufacturing cost, and an oxygen vacancy adsorbent for removing formaldehyde and a method for manufacturing the same An object of the present invention is to provide a non-woven fabric filter applied thereto.

A method for producing an oxygen vacancy adsorbent for removing formaldehyde according to the present invention for achieving the above object is as follows.

Oxygen vacancy adsorbent for formaldehyde removal is a first step of preparing a solution containing glucose, a manganese dioxide precursor, and water; a second step _{of reacting the solution to synthesize manganese dioxide (MnO 2} ) to which glucose, which is a reaction product, is bound; Step 3 to obtain a filtrate by filtering the solution containing the reaction product performed in Step 2; 4 step of washing the filtrate with distilled water; Step 5 of drying the washed filtrate to obtain a dry product; and calcining the dried material under an inert gas under 200 to 280° C. for 20 to 60 minutes to prepare an oxygen vacancy adsorbent; It is manufactured by a manufacturing method comprising a.

In step 1, the solution may contain the glucose and the manganese dioxide precursor in a weight ratio of 1:5 to 1:7.

In a preferred embodiment of the present invention, the manganese dioxide precursor is potassium permanganate (KMnO ₄ ), manganese acetate (Mn(CH ₃ CO ₂ ) ₂ ), sodium permanganate (NaMnO ₄ ) and manganese sulfate (MnSO ₄ ) Among It may include one or more types.

In a preferred embodiment of the present invention, the reaction of the second step may be carried out by bathing and stirring for 5 to 25 minutes under 60 to 100 °C.

In a preferred embodiment of the present invention, the drying in the 4 steps may be performed for 10 to 14 hours under 80 ~ 130 ℃.

As another object of the present invention, it is possible to prepare an oxygen vacancy adsorbent for removing formaldehyde through the above-described manufacturing method.

The oxygen vacancy adsorbent includes a calcined product obtained by calcining glucose-bound manganese dioxide (MnO ₂ ), and may have a specific surface area of 191.5 to 210.0 m ² ·g ⁻¹ .

In a preferred embodiment of the present invention, the oxygen vacancy adsorbent may have a hardness of 95.0 to 99.0% as measured by the KCM 1802 standard.

In a preferred embodiment of the present invention, the oxygen vacancy adsorbent may have a formaldehyde removal rate of 50 to 90%.

As another object of the present invention, it is possible to prepare a formaldehyde adsorption coating solution comprising 0.5 to 5.0 wt% of an oxygen vacancy adsorbent and the remaining amount of the binder solution.

In addition, a non-woven fabric filter for removing formaldehyde including the formaldehyde adsorption coating solution can be prepared.

Through the present invention, it is possible to manufacture an economical adsorbent that is not only efficient in removing gaseous pollutants such as formaldehyde, but also has a relatively low manufacturing cost, and a formaldehyde adsorption coating solution and a nonwoven filter containing the same can be manufactured.

1 (a) is an image taken of the oxygen vacancy adsorbent prepared in Example 1, (b) is an image taken of the adsorbent prepared in Comparative Example 1, (c) is Comparative Example 2 is an image taken of the adsorbent prepared in (d) is an image taken of the adsorbent prepared in Comparative Example 3, (e) is an image taken of the adsorbent prepared in Comparative Example 4.
2 is a design diagram of a chamber used for static evaluation, specifically, a cuboid made of an acrylic material having a volume of 160L, and forms a sealed condition when the door treated with rubber packing and rivets is closed.
3 is a design diagram of a chamber used for evaluating the performance of a nonwoven filter, specifically, an ^{acrylic cube having a volume of 1 m 3} , and the door portion is finished with rubber packing and rivets for internal sealing.
4 is a photograph taken of a chamber used for evaluating the performance of a nonwoven filter. Inside the chamber, a vent (used to ventilate the inside of the chamber by connecting it to a hood after the end of the experiment), a heater (for vaporizing formaldehyde). ), a circulation fan (used to spread the vaporized formaldehyde evenly in the chamber), and an air purifier.
5 is a graph showing the results of a formaldehyde removal experiment performed in Experimental Example 5;

The present invention will be described in more detail through the method for preparing an oxygen vacancy adsorbent for removing formaldehyde of the present invention.

A method for preparing an oxygen vacancy adsorbent for formaldehyde removal includes a first step of preparing a solution containing glucose, a manganese dioxide precursor, and water; a second step _{of reacting the solution to synthesize manganese dioxide (MnO 2} ) to which glucose, which is a reaction product, is bound; Step 3 to obtain a filtrate by filtering the solution containing the reaction product performed in Step 2; 4 step of washing the filtrate with distilled water; Step 5 of drying the washed filtrate to obtain a dry product; and calcining the dried material to prepare an oxygen vacancy adsorbent; manufactured through

The solution of step 1 may be characterized in that glucose and the manganese dioxide precursor are added in a weight ratio of 1: 5 to 1: 7, preferably 1: 5.2 to 1: 6.8 by weight. If a relatively small amount of glucose is added, there may be a problem in that the reactivity of manganese dioxide is lowered, and when a relatively small amount of the manganese dioxide precursor is added, there may be a problem in that the formaldehyde removal rate is reduced.

In addition, the manganese dioxide precursor is potassium permanganate (KMnO ₄ ), manganese acetate (Mn(CH ₃ CO ₂ ) ₂ ), sodium permanganate (NaMnO ₄ ) and manganese sulfate (MnSO ₄ ) It may be characterized as one or more, but is not particularly limited thereto.

The reaction of step 2 is carried out by bathing and stirring for 5 to 25 minutes at 60 to 100° C., preferably, it may be carried out at 65 to 95° C. for 10 to 20 minutes.

Drying in step 4 may be dried at 80 ~ 130 ℃ for 10 ~ 14 hours, preferably at 75 ~ 125 ℃ may be dried for 11 ~ 13 hours.

The calcination of step 6 is carried out under an inert gas, and is carried out under 200 to 280 ° C., preferably under 210 to 270 ° C., and is carried out under 200 to 280 ° C. for 20 to 60 minutes, preferably 25 to 55 minutes. During calcination, an oxygen vacancy adsorbent can be obtained. If calcined at a temperature of less than 200 ℃, there may be a problem that the structure of the particle is not deformed, when calcined at a temperature exceeding 280 ℃, there may be a problem that the oxygen vacancy structure is not formed. In addition, if the firing time is less than 20 minutes, there may be a problem that the structure of the particles is not deformed, and if the firing time exceeds 60 minutes, there may be a problem in that oxygen vacancy structures are not formed.

The oxygen vacancy adsorbent for formaldehyde removal prepared by the above-described method may include a calcined product obtained by calcining _{glucose-bound manganese dioxide (MnO 2 ).}

The oxygen vacancy is in the form of insufficient oxygen in the molecular structure, and has strong reactivity to actively cause the formaldehyde oxidation reaction. The presence of such oxygen vacancies can be confirmed with a specific surface area, and the oxygen vacancy adsorbent has ^{a specific surface area of 191.5 to 210.0 m 2} ·g ^-1 , and preferably has a specific surface area of 192.0 to 209.5 m ² ·g ^-1 may be having If the specific surface area is ^{less than 191.5 m 2} ·g ^-1 , there may be a problem in that the adsorption performance of the adsorbent is deteriorated.

In addition, the oxygen vacancy adsorbent may have a hardness of 95.0 to 99.0%, preferably 96.0 to 99.0%, and more preferably 96.5 to 99.0%, as measured by the KCM 1802 standard.

In addition, the oxygen vacancy adsorbent may have a formaldehyde removal rate of 50 to 90%, preferably 55 to 85%.

As another object of the present invention, it is possible to prepare a formaldehyde adsorption coating solution comprising the oxygen vacancy adsorbent and the binder solution.

In this case, 0.5 to 5.0 wt% of the oxygen vacancy adsorbent and the remaining amount of the binder solution may be included, and preferably 1.0 to 4.0 wt% of the oxygen vacancy adsorbent. If it is included in less than 0.5 wt %, there is a problem in that the formaldehyde removal rate is significantly reduced, and if it is included in excess of 5.0 wt %, there may be a problem of economic feasibility.

In addition, the binder solution may be at least one selected from an acrylic binder solution, a polyester-based solution, and a polyamide-based solution, but is not particularly limited thereto.

As another object of the present invention, a nonwoven fabric filter for removing formaldehyde may be manufactured by applying the formaldehyde adsorption coating solution to a nonwoven fabric.

The non-woven fabric filter for removing formaldehyde may be applied to an air purifier, an air conditioner, and the like, but is not limited thereto.

In order to solve the above problems, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

[Example]

Example 1: Oxygen Vacancy Adsorbent (OV-G/MnO) ₂ ) Produce

(1) As a manganese dioxide precursor, _{12 g of KMnO 4} and 1.8 g of glucose were added to 100 mL of distilled water to prepare a solution.

(2) The solution was reacted by bathing and stirring at 80° C. for 15 minutes.

(3) The solution reacted in the above step was filtered to obtain a filtrate.

(4) The filtrate was washed with distilled water.

(5) The filtrate obtained in step (4) was dried at 105° C. for 12 hours to obtain a dried product.

(6) The dried product was calcined under argon (Ar) gas at a calcination temperature of 240° C. for 40 minutes to obtain an oxygen vacancy adsorbent.

In addition, an image of the obtained oxygen vacancy adsorbent is shown in Fig. 1 (a).

Example 2 ~ Example 7: Preparation of adsorbent

It was prepared in the same manner as in Example 1, but the calcination temperature and calcination time, and _{the weight ratio of glucose and KMnO 4} were prepared as shown in Table 1 below.

Comparative Example 1: Manganese dioxide (MnO ₂ ) adsorbent manufacturing

(1) As a manganese dioxide precursor, KMnO ₄ 20 g, (NH ₄ ) ₂ C ₂ O ₄ H ₂ O 8 g was added to 260 mL of distilled water to prepare a solution.

(2) The solution was stirred at a heating temperature of 90 DEG C using a heating stirrer at a rotation speed of 150 rpm.

(3) The solution stirred in the above step was filtered to obtain a filtrate.

(4) The filtrate was dried at a temperature of 30° C. for 10 hours to obtain a solid-type filtrate.

(5) The solid-type filtrate was calcined at a calcination temperature of 500° C. for 3 hours to obtain a manganese dioxide (MnO ₂ ) adsorbent.

In addition, an image of the obtained manganese dioxide (MnO ₂ ) adsorbent is shown in FIG. 1 ( b ).

Comparative Example 1: Manganese dioxide (MnO ₂ ) adsorbent manufacturing

(1) As a manganese dioxide precursor, KMnO ₄ 20 g, (NH ₄ ) ₂ C ₂ O ₄ H ₂ O 8 g was added to 260 mL of distilled water to prepare a solution.

(2) The solution was stirred at a heating temperature of 90 DEG C using a heating stirrer at a rotation speed of 150 rpm.

(3) The solution stirred in the above step was filtered to obtain a filtrate.

(4) The filtrate was dried at a temperature of 30° C. for 10 hours to obtain a solid-type filtrate.

(5) The solid-type filtrate was calcined at a calcination temperature of 500° C. for 3 hours to obtain a manganese dioxide (MnO ₂ ) adsorbent.

In addition, an image of the obtained manganese dioxide (MnO ₂ ) adsorbent is shown in FIG. 1 ( b ).

Comparative Example 2: Glucose-manganese dioxide (G/MnO ₂ ) adsorbent manufacturing

(1) As a manganese dioxide precursor, _{12 g of KMnO 4} and 1.8 g of glucose were added to 100 mL of distilled water to prepare a solution.

(2) The solution was transferred to a water bath and bathed at a temperature of 80° C. for 15 minutes.

(3) The solution obtained in the above step was filtered to obtain a filtrate.

(4) The filtrate was washed with distilled water.

(5) (4) The filtrate was dried at a drying temperature of 105° C. for 12 hours to obtain a glucose-manganese dioxide (G/MnO ₂ ) adsorbent.

Also, the obtained glucose-manganese dioxide (G/MnO ₂ ) image of the adsorbent is shown in FIG. 1 ( c ).

Comparative Example 3: Manganese dioxide (MnO ₂ ) + CeO ₂ Adsorbent manufacturing

_{CeO 2} powder purchased from Sigma Aldrich (<5 μm, 99.9% trace metals) and manganese dioxide (MnO ₂ ) of Comparative Example 1 were added in a 1:1 ratio, and the adsorbent (manganese dioxide (MnO ₂ ) + CeO ₂ ) was prepared.

In addition, an image obtained by photographing the prepared adsorbent (manganese dioxide (MnO ₂ ) + CeO ₂ ) is shown in FIG. 1(d).

Comparative Example 4: Manganese dioxide (MnO ₂ ) + FeSiO ₂ Adsorbent manufacturing

(1) A solution of 20.35 g of polyethylene glycol (PEG 400) in 100 mL of cyclohexane was heated and stirred at 50° C. for 10 minutes.

_{(2) 20mL of FeCl 3} aqueous solution and _{3.20 g of NH 3} aqueous solution were added to the solution in which step (1) was performed, and then aged for 3 hours.

(3) 5.4 g of tetraethyl orthosilicate was added to the solution in which step (2) was performed.

(4) 30 mL of isopropanol was added to the solution in which step (3) was performed.

(5) The solution obtained in step (4) was centrifuged to obtain a precipitate.

(6) The precipitate was dried at 60° C. for 24 hours to obtain _{FeSiO 2 .}

(7) The FeSiO ₂ and the manganese dioxide (MnO ₂ ) of Comparative Example 1 were added in a 1:1 ratio, and the mixture was mixed for 5 minutes to obtain _{an adsorbent (manganese dioxide (MnO 2} ) + FeSiO _{2 ).}

In addition, an image obtained by photographing the prepared adsorbent (manganese dioxide (MnO ₂ ) + FeSiO ₂ ) is shown in FIG. 1(e).

Comparative Example 5: Manganese dioxide (MnO ₂ ) adsorbent

Pure Spear's manganese dioxide (MnO ₂ ) adsorbent (Purelyst MD-101) was used.

Comparative Example 6: Manganese dioxide (MnO ₂ ) adsorbent

_{Manganese dioxide (MnO 2} ) adsorbent (Activate MnO ₂ ) manufactured by Hunan Minstrong Technology was used.

Comparative Example 7 to Comparative Example 12: Preparation of adsorbent

It was prepared in the same manner as in Example 1, but the calcination temperature and calcination time, and _{the weight ratio of glucose and KMnO 4} were prepared as shown in Table 1 below.

Firing temperature (℃) Firing time (min) Glucose: KMnO ₄ weight ratio Example 2 200 40 1: 6.67 Example 3 280 40 1: 6.67 Example 4 260 20 1: 6.67 Example 5 260 60 1: 6.67 Example 6 260 40 1: 5 Example 7 260 40 1:7 Comparative Example 7 150 40 1: 6.67 Comparative Example 8 320 40 1: 6.67 Comparative Example 9 260 10 1: 6.67 Comparative Example 10 260 70 1: 6.67 Comparative Example 11 260 40 1: 4 Comparative Example 12 260 40 1:8

Experimental Example 1: Adsorbent Performance Evaluation - Static Evaluation

In order to evaluate the adsorbent performance of Examples 1 to 7 and Comparative Examples 1 to 12, static evaluation was performed, and the formaldehyde removal rates of the adsorbents were compared and shown in Tables 2 and 3 below.

The static evaluation method is as follows.

(1) A chamber manufactured according to the Japanese Jema1467 standard was prepared.

(2) After injecting formaldehyde gas into the chamber, a leak test was performed to check whether there was a leak by measuring at 30-minute intervals for 2 hours.

(3) When there is no leakage in step (2), formaldehyde was vaporized to an initial concentration of 40 ppm in a chamber.

(4) (3) The concentration of formaldehyde in the chamber was measured after 30 minutes and compared with the initial concentration.

At this time, the gas detection tubes used for the measurement were Gastec's No.91 and No.91M, and the design of the chamber is shown in FIG. 2 .

Example 1 Addition (g) Initial concentration (ppm) Concentration (ppm) after 30 minutes Removal rate (%) 3 40 20 50.0 5 40 15 62.5 8 40 8 80.0 15 40 8 80.0 20 40 8 80.0 Comparative Example 1 Addition (g) Initial concentration (ppm) Concentration (ppm) after 30 minutes Removal rate (%) 2.5 40 30 25.0 4.4 40 25 37.5 6.9 40 25 37.5 10.5 40 28 30.0 Comparative Example 2 Addition (g) Initial concentration (ppm) Concentration (ppm) after 30 minutes Removal rate (%) 2 40 25 37.5 4 40 20 50.0 6 40 20 50.0 12 40 20 50.0 23 40 20 50.0 Comparative Example 3 MnO ₂ addition amount (g) CeO ₂ addition amount (g) Initial concentration (ppm) After 30 minutes (ppm) Removal rate (%) 4 4 40 25 37.5 7 7 40 25 37.5 10 10 40 25 37.5 25 25 40 25 37.5 Comparative Example 4 MnO ₂ addition amount (g) FeSiO ₂ addition amount (g) Initial concentration (ppm) After 30 minutes (ppm) Removal rate (%) 4 4 40 25 37.5 7 7 40 25 37.5 10 10 40 25 37.5 25 25 40 25 37.5

division Addition (g) Initial concentration (ppm) Concentration (ppm) after 30 minutes Removal rate (%) Example 2 8 40 12 70.0 Example 3 8 40 9.5 76.2 Example 4 8 40 11 72.5 Example 5 8 40 8.5 78.7 Example 6 8 40 10 75.0 Example 7 8 40 9.5 76.2 Comparative Example 7 8 40 18 55.0 Comparative Example 8 8 40 15 62.5 Comparative Example 9 8 40 20 50.0 Comparative Example 10 8 40 16 60.0 Comparative Example 11 8 40 23 42.5 Comparative Example 12 8 40 21 47.5

According to Table 2, when the static evaluation was performed by adding 5 g or more of Example 1 of the present invention, the formaldehyde removal rate of Example 1 was higher than that of the adsorbents of Comparative Examples 1 to 4, and Example 1 was excellent. It was found to be an adsorbent with performance. On the other hand, the adsorbents of Comparative Examples 1 to 4 showed a lower formaldehyde removal rate than the adsorbent of Example 1 even when the amount of the adsorbent was changed.

Referring to Table 3, it was confirmed that Examples 2 to 7 showed a high removal rate of formaldehyde removal rate of 70% or more.

On the other hand, in the case of Comparative Example 7, in which the calcination temperature was carried out at less than 200°C, there was a problem in that the formaldehyde removal rate was sharply decreased, compared to Examples 1 and 2 (200°C), which was that the pores in the adsorbent were It is judged that this is because it was not properly formed, and in the case of Comparative Example 8, which was carried out at a calcination temperature of 280 ° C., when compared with Examples 1 and 3 (280 ° C), the formaldehyde removal rate was rather sharply decreased, It is considered that the size of the pores in the adsorbent is too large, and the formaldehyde removal rate is rather decreased.

In addition, in the case of Comparative Example 9, in which the calcination time was carried out for less than 20 minutes, there was a problem in that the formaldehyde removal rate was sharply decreased as compared to Examples 1 and 4 (20 minutes), which was because the calcination time was too short. It is judged that it is because the pores in the adsorbent were not properly formed, and in Comparative Example 10, which was carried out for a calcination time of more than 60 minutes, the formaldehyde removal rate was rather rapid compared to Examples 1 and 5 (60 minutes). However, it is judged that the formaldehyde removal rate was rather decreased because the pore size in the adsorbent became too large because the calcination time was excessively long.

In Comparative Example 11, although the glucose content in the adsorbent is high, the _{amount of formaldehyde that can be adsorbed is small because the amount of MnO 2} is relatively small, and as a result, it is determined that the removal rate is reduced.

In Comparative Example 12 _{, although the amount of MnO 2} in the adsorbent was large, it was confirmed that there was a problem in that the amount of glucose performing an auxiliary role _{of MnO 2} as nano-carbon was relatively small, so that the removal rate of formaldehyde was rapidly reduced.

Experimental Example 2: Measurement of specific surface area

The specific surface areas of the adsorbents of Example 1 and Comparative Examples 1 to 2 and Comparative Examples 5 to 6 were measured using a gas adsorption specific surface area analysis method. Specifically, nitrogen gas was adsorbed to the sample to determine the sample surface. The specific surface area was measured by measuring the amount of gas present in the . In this case, as a measuring device, a BELSORP-max specific surface area porosity analyzer manufactured by BEL INC was used.

As a result, Example 1, 192.64 m ² · g ^-1, Comparative Example 1 is 2.48 m ² · g ^-1, comparative example 2 is 28.44 m ² · g ^-1, in Comparative Example 5 is 91.95 m ² · g ^{- 1} , Comparative Example 6 was found to have a specific surface area ^{of 191.23m 2} ·g ^{-1 .} Through this, it was found that Example 1 had the highest specific surface area, and Example 1 was an adsorbent having higher adsorption performance than Comparative Example.

Experimental Example 3: Measurement of hardness

Examples 1 to 5 and Comparative Examples 7 to 10 In order to evaluate the durability of the adsorbent, hardness was measured and shown in Tables 4 and 5 below.

The hardness measurement was evaluated according to the KSM 1802 standard. Specifically, a particulate sample is sieved together with a steel ball, the weight of the sample remaining on the sieve is calculated, and the hardness is calculated by the ratio of the original sample weight. A 4×8 mesh sieve was used for hardness measurement, and it was performed at a temperature of 20 to 21° C. and a humidity of 20 to 30%. In order to increase the reliability of hardness measurement, experiments were performed 5 times. The formula for calculating the hardness is as follows.

In the above formula, H means hardness (%), W means the weight of the remaining sample on the sieve, and S means the weight of the sample before shaking.

Classification/Hardness (%) Primary Secondary tertiary 4th 5th average Example 1 98.2 97.5 96.8 97.3 97.1 97.4%

As shown in Table 4, the adsorbent of Example 1 exhibited an average hardness of 97.4%, and it was found that it was a highly durable adsorbent that was hard and does not abrade or break due to collisions between particles.

division hardness average Example 2 98.1% Example 3 96.3% Example 4 97.9% Example 5 96.7% Comparative Example 7 98.8% Comparative Example 8 87.5% Comparative Example 9 98.2% Comparative Example 10 89.7%

Referring to Table 5, Examples 2 to 5 were found to have excellent hardness together with Example 1.

On the other hand, Comparative Example 7, in which the calcination temperature was carried out at less than 200 ° C., was less calcined and less oxygen vacancies were generated, so that the hardness was high, compared with Examples 1 and 2 (200 ° C.), but the form There was a problem with the low aldehyde removal rate, and in the case of Comparative Example 8, which was carried out at a calcination temperature of 280 ° C., when compared with Examples 1 and 3 (280 ° C.), it was found that the hardness dropped sharply, which was the calcination temperature is too high, and oxygen vacancies are excessively formed.

In addition, in the case of Comparative Example 9, in which the firing time was less than 20 minutes, compared with Examples 1 and 4 (20 minutes), the hardness was high because the firing was less and oxygen vacancies were less generated, but the form There was a problem in that the aldehyde removal rate was low, and in the case of Comparative Example 10, which was carried out for a calcination time of more than 60 minutes, when compared with Examples 1 and 5 (60 minutes), it was found that the hardness dropped sharply, which was the calcination time It is thought that this is because the oxygen vacancy is excessively long.

Preparation Example 1: Preparation of non-woven filter

(1) Prepared by cutting the non-woven fabric into the size (300mm×400mm) to fit inside the air purifier.

(2) 1.575 wt% of the adsorbent of Example 1 and 500 mL of an aqueous acrylic binder solution (Youngwoo Kimtech, AK-9117+AK-990) of the remaining amount were stirred at a rotation speed of 280 rpm to prepare a formaldehyde adsorption coating solution.

(3) The formaldehyde adsorption coating solution was evenly applied to the nonwoven fabric.

(4) The nonwoven fabric subjected to step (3) was dried at room temperature for 24 hours to prepare a nonwoven fabric filter.

Comparative Preparation Example 1: Preparation of non-woven filter

It was prepared in the same manner as in Preparation Example 1, but using the adsorbent of Comparative Example 1.

Comparative Preparation Example 2: Preparation of non-woven filter

It was prepared in the same manner as in Preparation Example 1, but using the adsorbent of Comparative Example 2.

Experimental Example 5: Evaluation of non-woven filter performance

Formaldehyde removal performance of the nonwoven fabric filters of Preparation Example 1 and Comparative Preparation Example 1 to Comparative Preparation Example 2 were evaluated in the following manner, and are shown in Tables 6 and 5 below.

(1) After checking whether there are any abnormalities in the equipment and equipment, a leak test was performed.

(2) A non-woven filter was installed in an air purifier (Woongjin Coway, AP-1009JH).

(3) 0.3 mL of formaldehyde solution was put into the chamber.

(4) The formaldehyde solution was vaporized at a temperature of 65° C. using a heater.

(5) Turn off the heater after vaporization.

(6) The initial formaldehyde gas concentration was measured using a dinitrophenylhydrazine (DNPH) cartridge.

(7) The air purifier was operated and measurements were made 4 times at 30-minute intervals.

In addition, a design diagram of the chamber is shown in FIG. 3 , and an image of the actually manufactured chamber is shown in FIG. 4 .

division capture time Early 30 minutes later after 60 minutes after 90 minutes after 120 minutes Preparation Example 1 formaldehyde concentration
(ppm) 5.082 1.876 0.863 0.691 0.070 Removal rate (%) 0 63.09 83.02 86.40 98.62 Comparative Preparation Example 1 formaldehyde concentration
(ppm) 6.284 6.051 5.341 4.805 4.320 Removal rate (%) 0 3.7 15.00 23.54 31.26 Comparative Preparation Example 2 formaldehyde concentration
(ppm) 7.446 5.947 3.967 3.334 2.905 Removal rate (%) 0 20.14 46.73 55.23 60.99

As shown in Table 6, the nonwoven filter of Preparation Example 1 showed a formaldehyde removal rate of 80% or more after 60 minutes, but Comparative Preparation Example 1 and Comparative Preparation Example 2 showed a significantly lower removal rate than this.

In addition, as can be seen from FIG. 5, the initial concentration of formaldehyde was about 5 ppm at 1.876 ppm after 30 minutes, 0.863 ppm after 1 hour, 0.691 ppm after 1 hour and 30 minutes, and 0.070 ppm after 2 hours, about 63% of the initial concentration after 30 minutes. The removal rate was achieved, and it was found that the removal rate was close to 100% with a maximum of about 98% after 2 hours. Through this, it is judged that the good performance of the nonwoven filter of Preparation Example 1 is that glucose improves the adsorption capacity like activated carbon as nano-carbon, and the oxygen vacancy structure oxidizes formaldehyde quickly.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (10)

Step 1 of preparing a solution containing glucose, a manganese dioxide precursor, and water;
a second step _{of reacting the solution to synthesize manganese dioxide (MnO 2} ) to which glucose, which is a reaction product, is bound;
Step 3 to obtain a filtrate by filtering the solution containing the reaction product performed in Step 2;
4 step of washing the filtrate with distilled water;
Step 5 of drying the washed filtrate to obtain a dry product; and
Step 6 of calcining the dried material under an inert gas under 200 to 280° C. for 20 to 60 minutes to prepare an oxygen vacancy adsorbent;
A method for producing an oxygen vacancy adsorbent for removing formaldehyde comprising a.
The method of claim 1, wherein the solution comprises the glucose and the manganese dioxide precursor in a weight ratio of 1:5 to 1:7.
According to claim 1, wherein the manganese dioxide precursor is potassium permanganate (KMnO ₄ ), manganese acetate (Mn(CH ₃ CO ₂ ) ₂ ), sodium permanganate (NaMnO ₄ ) and manganese sulfate (MnSO ₄ ) Among A method for producing an oxygen vacancy adsorbent for removing formaldehyde, comprising at least one selected type.
The method of claim 1, wherein the reaction of step 2 is carried out by bathing and stirring for 5 to 25 minutes under 60 ~ 100 ℃,
Step 4 drying is a method for producing an oxygen vacancy adsorbent for removing formaldehyde, characterized in that it is carried out for 10 to 14 hours under 80 to 130 ℃.
An oxygen vacancy adsorbent for removing formaldehyde prepared by the method of any one of claims 1 to 4.
According to claim 5, Glucose-coupled manganese dioxide (MnO ₂ ) Includes a calcined product,
Oxygen vacancy adsorbent for formaldehyde removal with specific surface area of 191.5 ~ 210.0 m ² ·g ^-1.
The oxygen vacancy adsorbent for removing formaldehyde according to claim 6, wherein the oxygen vacancy adsorbent has a hardness of 95.0 to 99.0% measured according to KCM 1802 standard.
The oxygen vacancy adsorbent for removing formaldehyde according to claim 6, wherein the oxygen vacancy adsorbent has a formaldehyde removal rate of 50 to 90%.
A formaldehyde adsorption coating solution comprising 0.5 to 5.0 wt% of the oxygen vacancy adsorbent of any one of claims 6 to 8 and the remaining amount of the binder solution.
A nonwoven fabric filter for removing formaldehyde, characterized in that it contains the formaldehyde adsorption coating solution of claim 9.

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