KR102521252B1 - Filter and Method for Manufacturing Filter - Google Patents

Abstract

The present invention is a base unit; a hollow fiber membrane penetrating the inside of the base unit; And a metal wire disposed in the hollow of the hollow fiber membrane; a filter comprising a filter, and a method for manufacturing a filter comprising the step of inserting the hollow fiber membrane into which the metal wire is inserted into the hollow so as to pass through the inside of the base unit. to provide.

Description

Filter and manufacturing method of filter {Filter and Method for Manufacturing Filter}

The present invention relates to filters and methods of making filters.

A general air purifier consists of a filter (synthetic resin) for filtering suspended particulate matter, a filler (activated carbon) for adsorption of volatile organic molecules or harmful gases, and a dust collection filter (electrode) by generating static electricity. It can be reused or replaced with a new filter. Activated carbon used for adsorption also has a function of adsorbing harmful gases, but likewise cannot be reused after a certain period of time, so it must be replaced with new activated carbon.

In addition, the harmful gas adsorbed on the activated carbon is not decomposed but is temporarily fixed in the micropores (pores) of the activated carbon by electrostatic attraction, hydrogen bonding, or van der Waals force. Depending on the change in , it may flow out from the activated carbon, and when it reaches the limit of the adsorption capacity, there is a problem in that the harmful gas cannot be adsorbed any more.

Therefore, research on a filter that can efficiently adsorb fine dust and harmful gases in the air without the need for replacement or cleaning without using activated carbon has been attempted. In particular, there is an attempt to use a microorganism-supporting filter capable of mineralizing components such as harmful gases adsorbed on activated carbon or the like through biological metabolism.

According to the results of various studies, the metabolism of aerobic bacteria for biological metabolism can be promoted by electrochemical oxidation-reduction reactions. Therefore, research on a filter capable of inducing an electrochemical oxidation-reduction reaction to continuously enable biological metabolism when microorganisms are supported while functioning as a filter for fine dust and harmful gases like conventional air purifiers has been continued. .

In order to solve the above problems, the present invention not only physically filters various components such as fine dust and harmful gases in the atmosphere (air), but also uses an electrochemical oxidation-reduction reaction to biologically decompose separated and adsorbed components. We want to provide a possible filter.

According to one embodiment of the present invention, the base unit; a hollow fiber membrane penetrating the inside of the base unit; It provides a filter comprising a; and a metal wire disposed in the hollow of the hollow fiber membrane.

Further, according to another embodiment of the present invention, a method for manufacturing a filter is provided, which includes inserting a hollow fiber membrane into which a metal wire is inserted into the hollow to pass through the inside of the base unit.

In addition to physically separating fine dust and harmful gases, the filter of the present invention promotes an electrochemical oxidation-reduction reaction when microorganisms (aerobic bacteria, etc.) are supported on the filter, so that the components adsorbed through the biological metabolism of microorganisms Since it can be biologically degraded, unlike conventional air purifiers, it is not necessary to replace filters, activated carbon, etc., thereby reducing the user's effort, economically beneficial, and providing a filter with excellent efficiency.

1 is a diagram showing a filter according to an embodiment of the present invention.
2 is a view showing a counter electrode of Example 1 of the present invention.
3 is a view showing a SEM picture of the hollow fiber membrane used in Example 1 of the present invention.
4 is a view showing a filter of Example 1 of the present invention.
5 is a diagram showing the specific resistance value measured at a humidity of 68.6% according to Experimental Example 2 of the present invention.
6 is a diagram showing resistivity values measured at a humidity of 71.6% according to Experimental Example 2 of the present invention.
7 and 8 are views showing the results of metagenome analysis of the enriched cultured bacterial community according to Experimental Example 3 of the present invention.
9 is a result of confirming the concentration of microorganisms after applying a voltage of 3 to 5 volts according to Experimental Example 3 of the present invention.
10 is a view showing a glove box used in Experimental Example 3 of the present invention.
11 is a diagram showing the results of observing changes in hydrocarbon concentration in a filter not inoculated with a bacterial community enriched in culture according to Experimental Example 3 of the present invention.
12 is a diagram showing the results of observing the change in hydrocarbon concentration of the filter inoculated with the enriched cultured bacterial community according to Experimental Example 3 of the present invention.

Hereinafter, the present invention will be described in detail.

1. Filter

The present invention provides a filter.

A filter according to an embodiment of the present invention includes a base unit; a hollow fiber membrane penetrating the inside of the base unit; and a metal wire disposed in the hollow of the hollow fiber membrane.

The filter can be understood as a concept of a device that filters foreign substances in liquid or gas, and both filters and filter papers can be used as the same concept as filters, and the filters include filters for air purifiers, filters for masks, filters for air conditioners, It can be applied without limitation as long as it filters liquid or gas, such as an electrostatic filter or a HEPA filter.

In addition to filtering air pollutants (fine dust, harmful gases (hydrocarbons (methane, propane, butane, etc.), carbon monoxide, nitrogen oxide, butanol, propanol, etc.) generated from household gas stoves), the filter prevents biological degradation. An electrochemical oxidation-reduction reaction can be used for this. The electrochemical oxidation-reduction reaction can be maintained if the potential difference between the working electrode and the counter electrode is maintained, but the oxidation-reduction reaction, which is maintained unilaterally, is caused by environmental factors It does not affect the growth and metabolism of microorganisms, and it can cause corrosion of the electrode where the oxidation reaction is maintained. By repeating it, it is possible to induce the growth environment of microorganisms to change and to prevent corrosion of the electrode.

The working electrode is an electrode where the reaction of interest, that is, actually occurs, and the counter electrode is an electrode that allows the entire circuit to be completed (potential is applied and current can flow). The counter electrode is also referred to as an auxiliary electrode.

At this time, current flows through the working electrode to the counter electrode, and oxidation-reduction reactions always occur in pairs, and if a reduction reaction occurs at the working electrode, an oxidation reaction occurs at the counter electrode.

The substrate portion may include a fibrous structure. For example, the substrate may include a nonwoven fabric. Nonwoven fabric includes a fibrous structure having a fabric shape in which fibers are bonded to each other by chemical action, mechanical action, or appropriate moisture and heat treatment without processes such as spinning, weaving, and knitting, and includes natural fibers and synthetic fibers. , regenerated fibers, glass, carbon fibers, inorganic fibers and the like can be used.

The nonwoven fabric may be manufactured by a known method, and is generally formed by a web forming and bonding process and a processing process, but is not limited thereto.

The base unit may have a fibrous structure in the form of a non-woven fabric, and may have a structure in which gas (air) may pass and microorganisms (eg, aerobic bacteria) may be attached and grow.

The base part may include carbon fiber. The carbon fibers (graphite fibers) refer to fine fibers mainly composed of carbon. Carbon atoms constituting the carbon fiber are attached in the form of hexagonal ring crystals along the length direction of the fiber, and due to this molecular arrangement structure, they have strong physical properties, are stable even at high temperatures, and have excellent chemical stability.

In addition, when the substrate portion includes carbon fiber, it can be used as an electrode that induces an electrochemical oxidation-reduction reaction of the filter due to the excellent conductivity of the carbon fiber.

The hollow fiber membrane is a hydrogen ion (proton ) or metal ions can pass between the electrodes, i.e. between the anode and cathode, or between the working electrode and the counter electrode.

Specifically, in the filter of the present invention, the substrate portion may serve as a working electrode, the metal wire may serve as a counter electrode, and the hollow fiber membrane may be disposed between the substrate portion and the metal wire. .

However, since such a hollow fiber membrane is difficult for air to pass through, it is not suitable as a filter for an air purifier, and must be disposed between the substrate and the metal wire in a specific structure. Accordingly, the filter of the present invention may use a hollow fiber membrane so that the metal wire of the wire type is used as a counter electrode and inserted into a substrate used as a working electrode.

The hollow fiber membrane may have an outer diameter of 1 to 2 mm and an inner diameter of 0.5 to 0.9 mm, and the material of the hollow fiber membrane may include polyolefins.

When the outer diameter and the inner diameter of the hollow fiber membrane satisfy the above ranges, the metal wire can be well fixed in the hollow of the hollow fiber membrane, so that both electrodes (working electrode/counter electrode) required for the electrochemical oxidation-reduction reaction can be electrochemically can be separated by

The polyolefins may include polyethylene, polypropylene, polybutylene, polymethylene, polybutene-1, polyisobutylene, etc., but are not limited thereto.

The hollow fiber membrane may include micropores, and the micropores may be uniformly distributed from an outer surface to an inner surface of the hollow fiber membrane.

The average pore size of the micropores may be 0.001 to 0.1 μm. When the average pore size of the micropores of the hollow fiber membrane satisfies the above range, the permeation of ions (hydrogen ion, ammonium, nitrate, phosphate, sulfate, etc.) and moisture may be allowed, so that electricity is generated between the working electrode and the counter electrode. A chemical oxidation-reduction reaction can be induced efficiently.

The average pore size of the micropores can be measured using an electron microscope.

The hollow fiber membrane may electrochemically separate the substrate part and the metal wire. That is, the hollow fiber membrane generates a potential difference between the substrate (working electrode) and the metal wire (counter electrode) by including a metal wire in the hollow of the hollow fiber membrane without interfering with the passage of air through the substrate, thereby electrochemically It may be disposed penetrating the inside of the substrate to induce an oxidation-reduction reaction.

In addition, a plurality of hollow fiber membranes may be spaced apart and penetrated inside the base unit.

The number of hollow fiber membranes inserted so that the total length of the portion inserted into the substrate portion is 3 to 5 times the average length of the horizontal and vertical lengths of the substrate portion may be disposed through the inside of the substrate portion. .

The metal wire may be disposed in the hollow of the hollow fiber membrane, and the metal wire may act as a counter electrode to form a potential difference with the substrate part.

The metal wire may include a platinum wire or a gold wire.

The metal wire may have a diameter of 0.4 to 0.6 mm.

On the other hand, a potential difference is formed between the base part and the metal wire, and water is required for ions to pass through. However, there is a limit in that the filter cannot be manufactured in a structure wet with water. Accordingly, the substrate may be treated with a hydrophilic material so as to maintain an appropriate humidity in the substrate. That is, the substrate may be impregnated with the hydrophilic material.

As the base material impregnated with the hydrophilic material is used, there is an advantage in not having to artificially supply moisture to the filter.

The hydrophilic material may include a hydrophilic functional group including at least one selected from a hydroxy group and an amine group. Specifically, the hydrophilic material may be a material that includes the hydrophilic functional group but is insoluble in water.

For example, the hydrophilic material may include chitosan. The chitosan is a linear polysaccharide composed of D-glucosamine and N-acetylglucosamine, and can be obtained by treating crustacean shells such as crabs and shrimps with sodium hydroxide base. The chitosan contains both a hydroxyl group and an amine group in the molecule and is soluble in acetic acid, so it is easy to impregnate the base material, and it is insoluble in water, so it has resistance and/or stability to humidity or moisture. Therefore, the chitosan can be stably impregnated into the base material.

The substrate may further include an acid. Specifically, the base material impregnated with the hydrophilic material may further include an acid.

Hydrogen ions (protons) generated by dissociation of the acid may form a salt through a coordination bond with an amine group of chitosan, and thus may absorb moisture in the air and act as an electrolyte.

The acid may include phosphoric acid and the like.

As described above, the filter may further include microorganisms supported on the substrate for biological decomposition after filtering/adsorbing pollutants in the air.

For example, the microorganisms may include aerobic bacteria and the like. Specifically, the aerobic bacteria are bacteria that obtain energy by oxidizing a substrate using free oxygen, and are also called aerobic bacteria. arplatensis , etc.

As described above, the filter of the present invention may include a microorganism-supporting filter obtained by supporting microorganisms.

2. Manufacturing method of filter

The present invention provides a method for manufacturing a filter.

A method of manufacturing a filter according to an embodiment of the present invention may include inserting a hollow fiber membrane in which a metal wire is inserted into the hollow to pass through the inside of the base unit.

Specifically, the manufacturing method of the filter, A) inserting a hollow fiber membrane to pass through the inside of the base unit; and B) inserting a metal wire into the hollow of the hollow fiber membrane; or a) inserting a metal wire into the hollow of the hollow fiber membrane; and b) inserting the hollow fiber membrane into which the metal wire is inserted to pass through the inside of the base unit.

In the step of inserting the hollow fiber membrane to penetrate the inside of the base unit, after penetrating the inside of the base unit using a needle having an inner diameter about twice the diameter of the hollow fiber membrane, the hollow fiber membrane or metal A step of inserting the hollow fiber membrane into which the wire is inserted may be included.

The manufacturing method of the filter may further include hydrophilizing the substrate by treating a hydrophilic material.

For example, before or after the hollow fiber membrane (or the hollow fiber membrane into which the metal wire is inserted) is inserted into the base part, it may further include treating the base part with a hydrophilic material to make it hydrophilic.

It may further include treating the base material with a hydrophilic material to make it hydrophilic before step A), or treating the base material to make it hydrophilic before step a) or step b). may include

The step of hydrophilizing the substrate may include immersing the substrate in a solution containing a hydrophilic material, and impregnating the substrate with the hydrophilic material by immersing the substrate in a solution containing a hydrophilic material as described above. can

As the substrate is impregnated with a hydrophilic material, the substrate can maintain an appropriate humidity, and the substrate impregnated with the hydrophilic material is used, so there is no need to artificially supply moisture to the filter.

The step of hydrophilizing the substrate may include, in detail, immersing the substrate in the hydrophilic material-containing solution and then leaving the substrate under a pressure of about 0.1 atm until no bubbles are generated.

Subsequently, a step of drying the base material impregnated with the hydrophilic material may be further included. The drying step may include leaving the hydrophilic substance-containing solution at room temperature and normal pressure until the solution no longer flows out of the substrate, or may include drying at a temperature of 100 to 120 ° C. , or may be dried by including both of the above steps.

The hydrophilic material may include a hydrophilic functional group including at least one selected from a hydroxy group and an amine group. Specifically, the hydrophilic material may be a material that includes the hydrophilic functional group but is insoluble in water.

For example, the hydrophilic material may include chitosan. The chitosan is a linear polysaccharide composed of D-glucosamine and N-acetylglucosamine, and can be obtained by treating crustacean shells such as crabs and shrimps with sodium hydroxide base. The chitosan contains both a hydroxyl group and an amine group in the molecule and is soluble in acetic acid, so it is easy to impregnate the base material, and it is insoluble in water, so it has resistance and/or stability to humidity or moisture. Therefore, the chitosan can be stably impregnated into the base material.

The manufacturing method of the filter may further include impregnating the base material impregnated with the hydrophilic material in an acidic solution. Hydrogen ions (protons) generated by acid dissociation of the acidic solution may form a salt through a coordinate bond with an amine group of chitosan, and thus may absorb moisture in the air and act as an electrolyte.

The acidic solution may include a phosphoric acid solution and the like.

In the step of impregnating the base material impregnated with the hydrophilic material into the acidic solution, specifically, after immersing the base material in the acidic solution, put it in a desiccator and leave it under a pressure of about 0.1 atm until no bubbles are generated. steps may be included.

Subsequently, a step of drying the substrate part may be further included. The drying may include leaving the acid solution at room temperature and pressure until the acidic solution no longer flows out of the substrate, or may include drying at a temperature of 100 to 120 ° C., or It may also be dried by including both of the above steps.

The substrate portion may be used to include a fibrous structure. For example, a nonwoven fabric may be used as the base material. The nonwoven fabric may be manufactured by a known method, and is generally formed by a web forming and bonding process and a processing process, but is not limited thereto.

The base part may include carbon fiber. The carbon fibers are also referred to as graphite fibers, and mean fine fibers mainly composed of carbon. Carbon atoms constituting the carbon fiber are attached in the form of hexagonal ring crystals along the length direction of the fiber, and due to this molecular arrangement structure, they have strong physical properties, are stable even at high temperatures, and have excellent chemical stability. In addition, when the substrate portion includes carbon fiber, it can be used as an electrode that induces an electrochemical oxidation-reduction reaction of the filter due to the excellent conductivity of the carbon fiber.

The hollow fiber membrane is a hydrogen ion (proton ) or metal ions can pass between the electrodes, that is, between the anode and cathode, or between the working electrode and the counter electrode.

Specifically, the substrate portion may serve as a working electrode, the metal wire may serve as a counter electrode, and the hollow fiber membrane may be inserted between the substrate portion and the metal wire. However, such a hollow fiber membrane is not suitable as a filter for an air purifier because it is difficult for air to pass through, so it must be inserted between the base part and the metal wire in a specific shape. Accordingly, the filter of the present invention may use a hollow fiber membrane so that the metal wire of the wire type is used as a counter electrode and inserted into a substrate used as a working electrode.

The hollow fiber membrane may have an outer diameter of 1 to 2 mm and an inner diameter of 0.5 to 0.9 mm, and the material of the hollow fiber membrane may include polyolefins.

When the outer diameter and the inner diameter of the hollow fiber membrane satisfy the above ranges, the metal wire can be well fixed in the hollow of the hollow fiber membrane, so that both electrodes (working electrode/counter electrode) required for the electrochemical oxidation-reduction reaction can be electrochemically can be separated by

The polyolefins may include polyethylene, polypropylene, polybutylene, polymethylene, polybutene-1, polyisobutylene, etc., but are not limited thereto.

The hollow fiber membrane may include micropores, and the micropores may be uniformly distributed from an outer surface to an inner surface of the hollow fiber membrane.

The average pore size of the micropores may be 0.001 to 0.1 μm. When the average pore size of the micropores of the hollow fiber membrane satisfies the above range, the permeation of ions and moisture may be allowed, and thus an electrochemical oxidation-reduction reaction may be efficiently induced between the working electrode and the counter electrode.

As the hollow fiber membrane is inserted through the inside of the substrate portion, it is possible to electrochemically separate the substrate portion and the metal wire. That is, the hollow fiber membrane generates a potential difference between the substrate (working electrode) and the metal wire (counter electrode) by including a metal wire in the hollow of the hollow fiber membrane without interfering with the passage of air through the substrate, thereby electrochemically Oxidation-reduction reactions can be induced.

In addition, a plurality of hollow fiber membranes may be spaced apart and inserted through the inside of the base unit. The hollow fiber membranes may be inserted through the inside of the base unit by the number inserted so that the total length of the portion inserted into the base unit is 3 to 5 times the average length of the horizontal and vertical lengths of the base unit. .

The metal wire may be inserted into the hollow of the hollow fiber membrane, and the metal wire may act as a counter electrode to form a potential difference with the substrate part.

The metal wire may include at least one selected from a platinum wire and a gold wire.

The metal wire may have a diameter of 0.4 to 0.6 mm.

In the manufacturing method of the filter, after the step of inserting the hollow fiber membrane in which the metal wire is inserted into the hollow to penetrate the inside of the base member for biological decomposition after filtering/adsorbing pollutants in the air, microorganisms in the base member It may further include the step of supporting.

The method of supporting the microorganism on the substrate may include, but is not limited to, directly inoculating a microorganism-containing culture solution onto the substrate.

The microorganisms may include aerobic bacteria and the like. Specifically, the microorganism may include Pseudomonas putida , Rhodococcus pyridinivorans , Pseudomonas extremaustralis , Pseudomonas veroni , Pseudacidovorax intermedius , Microbacterium maritypicum , Achromobacter arplatensis , and the like.

The filter manufactured as described above can be used as a filter for an electrochemical air purifier, so unlike existing non-biological filters, it has excellent efficiency and has the economical advantage of not having to replace filters contaminated by biological decomposition. there is.

Hereinafter, the present invention will be described in more detail through examples. However, these examples are only for helping the understanding of the present invention, and the scope of the present invention is not limited to these examples in any sense.

<Production Example 1>

A carbon nonwoven fabric having a size of 100 mm X 100 mm X 10 mm and having a carbon content of 97 wt% or more is soaked in 99% ethanol for 30 minutes, then removed, soaked in ultra pure water, boiled for about 30 minutes, and then alcohol is removed. and dried at 110 °C for 3 hours.

A chitosan solution was prepared by dissolving 1 g of chitosan (Aldrich 419419, High molecular weight) in 1,000 ml of an acetic acid solution (2%). After the washing, the dried carbon nonwoven fabric was immersed in the chitosan solution, placed in a desiccator, and allowed to stand under a pressure of about 0.1 atm until no air bubbles were generated between the fibers of the carbon nonwoven fabric.

After the carbon nonwoven fabric was saturated with the chitosan solution, the carbon nonwoven fabric was taken out and hung in the air until the fluidity liquid no longer flowed out, and then completely dried at 110 ° C. to obtain a chitosan-impregnated carbon nonwoven fabric.

Subsequently, the chitosan-impregnated carbon nonwoven fabric was immersed in a 10 mM phosphoric acid solution, placed in a desiccator, and allowed to stand under a pressure of about 0.1 atm until no air bubbles were generated between the fibers of the carbon nonwoven fabric. The carbon nonwoven fabric saturated with the phosphoric acid solution was taken out of the phosphoric acid solution and hung in the air until the flowable liquid no longer flowed out, and then dried at 110 ° C. for 3 hours to obtain a carbon nonwoven fabric impregnated with chitosan and phosphoric acid.

<Comparative Preparation Example 1>

A carbon nonwoven fabric having a size of 100 mm X 100 mm X 10 mm and having a carbon content of 97 wt% or more is soaked in 99% ethanol for 30 minutes, then removed, soaked in ultra pure water, boiled for about 30 minutes, and then alcohol is removed. and dried at 110 °C for 3 hours, and a carbon nonwoven fabric obtained was used as an untreated control.

<Comparative Preparation Example 2>

The carbon nonwoven fabric of Comparative Preparation Example 1 was immersed in a 10 mM phosphoric acid solution, placed in a desiccator, and allowed to stand under a pressure of about 0.1 atm until no bubbles were generated between the fibers of the carbon nonwoven fabric. The carbon nonwoven fabric saturated with the phosphoric acid solution was taken out of the phosphoric acid solution and hung in the air until the flowable liquid no longer flowed out, and then dried at 110 ° C. for 3 hours to obtain a carbon nonwoven fabric impregnated with phosphoric acid.

<Example 1>

A hollow fiber membrane made of polypropylene (Sefratech Co., Ltd.) (FIG. 3) having an outer diameter of 1.35 mm and an inner diameter of 0.7 mm, having fine pores with a pore size of 0.001 to 0.1 μm is prepared, A counter electrode as shown in FIG. 2 was manufactured by inserting a Pt wire having a diameter of 0.5 mm into the hollow (hole) of the hollow fiber membrane.

A filter was manufactured by using the carbon nonwoven fabric of Preparation Example 1 as a working electrode and inserting the counter electrode prepared above into the carbon nonwoven fabric as shown in FIG. 4 .

<Comparative Example 1>

In Example 1, a filter was manufactured in the same manner as in Example 1, except that the carbon nonwoven fabric of Comparative Preparation Example 1 was used instead of the carbon nonwoven fabric of Preparation Example 1.

<Comparative Example 2>

In Example 1, a filter was manufactured in the same manner as in Example 1, except that the carbon nonwoven fabric of Comparative Preparation Example 2 was used instead of the carbon nonwoven fabric of Preparation Example 1.

<Experimental Example 1>

Moisturizing ability was compared by measuring the weight change of the carbon nonwoven fabric of Preparation Example 1 and the carbon nonwoven fabric of Comparative Preparation Examples 1 and 2.

After preparing three carbon nonwoven fabrics of Preparation Example 1 and Comparative Preparation Examples 1 and 2 each having a width of 100 mm, a cell of 100 mm, and a thickness of 10 mm, after drying at 110 ° C. for 3 hours, i) immediately after drying, ii) After exposure to 60% humidity, iii) the results of measuring the weight of the carbon nonwoven fabric after exposure to 90% humidity are shown in Table 1 below.

division Weight immediately after drying (mg) Weight after exposure to 60% humidity (mg) Weight after exposure to 90% humidity (mg) weight increase rate measurement average measurement average measurement average 60% humidity 90% humidity Comparative Preparation Example 1 Untreated 1 8,138 7871.3 8,148 7,882.0 8,150 7,886.3 0.14% 0.19% Untreated 2 7,627 7,637 7,641 Untreated 3 8,649 7,861 7,868 Comparative Preparation Example 2 phosphating 1 8,598 8,662.6 8,842 8,888.3 8,921 8,979.0 2.61% 3.65% phosphating 2 8,741 9,010 9,111 phosphating 3 8,506 8,813 8,905 Preparation Example 1 Chitosan-phosphating 1 8,752 8,870.6 9,371 9,444.0 9,552 9,625.0 6.46% 8.51% Chitosan-phosphating 2 8,897 9,433 9,614 Chitosan-phosphating 3 8,963 9,528 9,709

As shown in Table 1, in the case of the carbon nonwoven fabrics of Preparation Example 1 and Comparative Preparation Example 2, the weight increased. These results prove that chitosan and phosphoric acid have a function of absorbing moisture in the air by a hydrophilic functional group by structurally stably bonding to the carbon nonwoven fabric.

In particular, compared to the carbon nonwoven fabric of Comparative Preparation Example 1, the weight increase rate of the carbon nonwoven fabric of Comparative Preparation Example 2 treated with phosphoric acid and the weight increase rate of the carbon nonwoven fabric of Preparation Example 1 treated with chitosan-phosphate were about 19 times and about 45 times, respectively. It was confirmed that the increase was doubled, and it was confirmed that the salt produced by the combination of the amine group and the phosphoric acid group of chitosan can absorb moisture in the air more efficiently than when only phosphoric acid was treated.

Therefore, it is believed that the carbon nonwoven fabric of Preparation Example 1 treated with chitosan-phosphoric acid can absorb moisture in the air and enable fluidity of ions without artificially supplying moisture.

<Experimental Example 2>

The specific resistances of the filter of Example 1 and the filters of Comparative Examples 1 and 2 were compared.

The resistance between the working electrode and the counter electrode of the filter of Example 1 and the filter of Comparative Examples 1 and 2 was measured under conditions of humidity of 68.6% (FIG. 5) and 71.6% (FIG. 6), and the results are shown in Table 2 below. .

Working electrode (carbon non-woven fabric) counter electrode Resistivity (air humidity 68.6%) Resistivity (air humidity 71.6%) Comparative Preparation Example 1 Platinum wire (Pt wire) O.L (more than 2,000 MΩ) O.L (more than 2,000 MΩ) Comparative Preparation Example 2 Platinum wire (Pt wire) 11.78 MΩ 11.83 MΩ Preparation Example 1 Platinum wire (Pt wire) 1.255 MΩ 1.468 MΩ

According to Table 2, in the filter of Comparative Example 1, it was confirmed that the resistance between the working electrode and the counter electrode was above the measurement limit (Over Limited), indicating that there was no conductivity. Under the condition of 68.6% humidity, the resistivity between the working electrode and the counter electrode of the filter of Comparative Example 2 was 11.78 MΩ, which was about 9.4 times higher than the resistivity between the working electrode and the counter electrode of the filter of Example 1, which was 1.255 MΩ. On the other hand, under the condition of 71.6% humidity, the specific resistance between the working electrode and the counter electrode of the filter of Comparative Example 2 was 11.83 MΩ, which was about 8.1 times higher than the resistivity between the working electrode and the counter electrode of the filter of Example 1, which was 1.468 MΩ. .

Theoretically, when the air humidity is high, the moisture content in the carbon nonwoven fabric increases proportionally and the resistance value should decrease, but it was confirmed that the opposite phenomenon appeared. It is believed that this phenomenon is because the amount of moisture inside the carbon nonwoven fabric is proportional to the air humidity and inversely proportional to the temperature. In conclusion, the untreated carbon nonwoven fabric of Comparative Example 1 is suitable as a filter material for air purifiers based on conductivity, surface area, structure, etc., but cannot induce an electrochemical oxidation-reduction reaction, so it cannot be used for biological degradation. It was confirmed that it could not be

Therefore, it is necessary to modify the carbon nonwoven fabric with a hydrophilic functional group to enable ion exchange due to the potential difference with the counter electrode, and the hydrophilization of the carbon nonwoven fabric using chitosan and phosphoric acid, as in the filter of Example 1, increases the internal humidity within an appropriate range. It was confirmed that it can be maintained as , so it can be applied to electrochemical oxidation-reduction reactions.

<Experimental Example 3>

An experiment was conducted to measure the biological electrochemical activity of the filter of Example 1. The enriched cultured bacterial community has a metabolic function of hydrocarbons and nitrites because it was cultured with mixed hydrocarbons (methane, propane, butane) as the only carbon source and nitrite as the only nitrogen source.

The metagenome analysis results of the bacterial community enriched in the electrochemical reactor are shown in FIGS. 7 to 9.

Carbon non-woven fabric electrodes were attached to the culture solution of the electrochemical reactor and used as an anode and a cathode, respectively, and a voltage of 3 volt, 4 volt, and 5 volt was applied between the anode and the cathode, respectively, and as a result of enriched culture, FIGS. 7 to 9 and In the same incubator applied with a voltage of 4 volts, it was confirmed that Pseudomonas putida was enriched.

Therefore, the filter of Example 1 was inoculated with the culture solution to which a voltage of 4 volt was applied, and the metabolic activity of gaseous hydrocarbons was measured using a glove box manufactured as shown in FIG. 10 . When a hydrocarbon gas of a certain concentration was confined in the glove box and measured with a detector tube, the concentration did not change for more than 10 days. Therefore, the glove box was determined to be suitable for measuring the biological and electrochemical activity of the filter of Example 1.

For the control experiment, the filter of Example 1 (not inoculated with the culture solution applied with a voltage of 4 volts) was placed in a glove box filled with hydrocarbons at a certain concentration, and a voltage of 4 volts was applied to obtain hydrocarbon and carbon dioxide for 3 days. Changes were measured with a detector tube.

As a result of observing the concentration change of the hydrocarbon injected into the glove box while operating the filter of Example 1 mounted inside the glove box without inoculating the enriched cultured bacterial community, as shown in FIG. 11, 0.4% (4,000 ppm) for 3 days It was confirmed that the concentration of

On the other hand, the filter of Example 1 mounted inside the glove box was inoculated with a bacterial colony (culture medium applied with a voltage of 4 volt), and the concentration change of the hydrocarbon injected into the glove box was observed while operating, as shown in FIG. 12 It was confirmed that the concentration decreased to 0.2% (2,000 ppm) for 3 days.

On the other hand, it was confirmed that there was no clear change in the concentration of carbon dioxide (purple) in both the control group, which was not inoculated with the enriched cultured bacterial community, and the inoculated filter of Example 1.

In conclusion, the carbon nonwoven fabric used as the substrate of the present invention has good air permeability and excellent electrical conductivity, so it is suitable as a material for an electrochemical filter, but due to the nature of the air filter, it cannot be wetted or submerged in liquid Therefore, since it is necessary to maintain an appropriate level of moisture, it is necessary to modify a hydrophilic functional group capable of self-moisturizing by adsorbing moisture even at low humidity.

Chitosan is a high molecular compound having two hydroxyl groups and one amine group based on glucose monomers. It has the function of inhibiting the growth of microorganisms and is not soluble in water, so once impregnated into a carbon nonwoven fabric, it is likely to be lost by moisture or contamination. is low Therefore, it was found that electrical conductivity can be maintained by self-moisturizing in the air by modifying the carbon nonwoven fabric with a combination of chitosan and phosphoric acid as a cation donor.

The carbon nonwoven fabric of Example 1 ( It was confirmed that the carbon nonwoven fabric of Preparation Example 1) was suitable as a material for an electrochemical filter for an air purifier for biological decomposition.

Claims (28)

Ministry of Finance;
a hollow fiber membrane penetrating the inside of the base unit; and
a metal wire disposed in the hollow of the hollow fiber membrane;
including,
The substrate portion is a filter impregnated with a hydrophilic material. The method of claim 1,
The filter, the substrate portion comprising a carbon fiber. delete The method of claim 1,
The filter, wherein the hydrophilic material includes a hydrophilic functional group including at least one selected from a hydroxyl group and an amine group. The method of claim 1,
The hydrophilic material is a filter comprising chitosan. The method of claim 1,
The hydrophilic material is impregnated base material further comprises an acid, the filter. In claim 6,
The filter, wherein the acid comprises phosphoric acid. The method according to any one of claims 1, 2 and 4 to 7,
The hollow fiber membrane has an outer diameter of 1 to 2 mm and an inner diameter of 0.5 to 0.9 mm, the filter. The method according to any one of claims 1, 2 and 4 to 7,
The material of the hollow fiber membrane is a filter that includes polyolefins. The method according to any one of claims 1, 2 and 4 to 7,
The hollow fiber membrane includes micropores, and the average pore size of the micropores is 0.001 to 0.1 ㎛, the filter. The method according to any one of claims 1, 2 and 4 to 7,
A filter that penetrates a plurality of hollow fiber membranes spaced apart in the interior of the base unit. The method according to any one of claims 1, 2 and 4 to 7,
Wherein the metal wire includes at least one selected from a platinum wire and a gold wire. The method according to any one of claims 1, 2 and 4 to 7,
Wherein the metal wire has a diameter of 0.4 to 0.6 mm. The method of claim 1,
The filter, which further comprises microorganisms supported on the substrate. The method of claim 14,
The microorganism is a filter that includes aerobic bacteria. The method of claim 1,
Wherein the filter comprises a microorganism-supporting filter. inserting the hollow fiber membrane into which the metal wire is inserted into the hollow so as to pass through the inside of the base unit; and
hydrophilizing the substrate by treating a hydrophilic material;
A method for manufacturing a filter, comprising: The method of claim 17
A) inserting a hollow fiber membrane to penetrate the inside of the base unit; and
B) inserting a metal wire into the hollow of the hollow fiber membrane;
A method for manufacturing a filter, comprising: The method of claim 17
a) inserting a metal wire into the hollow of the hollow fiber membrane; and
b) inserting the hollow fiber membrane into which the metal wire is inserted so as to pass through the inside of the substrate;
A method for manufacturing a filter, comprising: delete The method of claim 17
In the step of hydrophilizing the base material,
A method for producing a filter comprising the step of impregnating the substrate with the hydrophilic material by immersing the substrate in a solution containing a hydrophilic material. The method of claim 17
The method of manufacturing a filter, wherein the hydrophilic material includes a hydrophilic functional group including at least one selected from a hydroxyl group and an amine group. The method of claim 17
The method of manufacturing a filter, wherein the hydrophilic material comprises chitosan. The method of claim 21,
Further comprising the step of drying the substrate portion impregnated with the hydrophilic material, the method for producing a filter. The method of claim 21,
Further comprising the step of impregnating the base material impregnated with the hydrophilic material in an acidic solution, the manufacturing method of the filter. The method of claim 25
The method of manufacturing a filter, wherein the acidic solution includes a phosphoric acid solution. The method according to any one of claims 17 to 19 and 21 to 26,
The manufacturing method of the filter, further comprising the step of supporting the microorganisms on the substrate. The method of claim 27
The method of manufacturing a filter, in which the microorganisms include aerobic bacteria.

Images