WO2023239099A1 - Air pollution source concentration and breakthrough system - Google Patents

Abstract

The present invention relates to an air pollution source concentration and breakthrough system comprising: a core formed from a conductive fiber; and a shell forming a yarn structure by being spun on the core, the yarn being formed from an adsorptive nanofiber. Thus, a minimum amount of an air pollution source concentrated on the shell is desorbed by means of the self-heating of the core, and thus high accuracy, selectivity, and portable measuring may be possible.

Description

Air pollutant concentration and breakthrough system

The present invention relates to an air pollutant concentration and breakthrough system, which concentrates and desorbs extremely small amounts of air pollutants by a solid-phase trace extraction method, wherein the desorption is achieved by self-heating without a separate heating device. It's about the system.

As public interest in air pollutants such as fine dust, soot, volatile organic compounds, and gases generated during combustion, synthesis, and decomposition increases, and as concerns about health increase, regulations on public use facilities and household odors are being implemented. there is.

Trace gaseous pollutants indoors and outdoors exist in extremely small amounts of ppm or less, and there is a need to selectively and accurately detect them. In particular, effective response to indoor and outdoor air pollutants is only possible when tracking and monitoring technology is included from the source to the receptor. To achieve this, water sensors must be installed at various points to detect pollutants in real time, and through this overall monitoring, the spread path of air pollutants can be identified. In order to secure many detection points from the point of generation of a pollutant to the receptor, inexpensive sensors that can be universally supplied that can accurately sense low-concentration pollutants are required. However, with current inexpensive semiconductor gas sensors, low-concentration air pollutants can be accurately and selectively detected. It is impossible.

NDIR (Non Dispersive Infra Red) is an optical measurement method that can analyze the concentration of specific components by using the fact that gaseous substances have _a specific absorption spectrum for infrared _rays . Portable detection is possible using a mobile communication terminal or smartphone with high precision. Non-patent Document 1 discloses a portable NDIR CO ₂ sensor that can measure CO ₂ concentration by combining it with a smartphone. However, the NDIR sensor has a disadvantage in that it has a large structure and is not cheap.

Solid-phase microextraction (SPME) is a method of detecting extremely small amounts of gaseous pollutants that are analyzed by GC/MS after concentrating (collecting) pollutants. It is implemented by the Ministry of Environment and can analyze even trace amounts of substances, so it is used in water, sewage, and Hydrocarbons such as odorous gases, total volatile organic compounds (TVOC), and formaldehyde (HCHO) can be detected in various environmental samples such as soil and livestock manure. As an example, Non-Patent Document 2 is a quantitative analysis of VOCs in atmospheric environmental samples by SPME. SPME fiber is used as CAR/PDMS fiber with VOCs selectivity, and the coating component or amount of coating on the fiber is adjusted to adsorb the target component. The adsorption characteristics are controlled.

In utilizing the solid phase trace extraction method, the present invention adopts a self-heating system to desorb air pollutants concentrated in the adsorbent through self-heating, thereby improving the performance of inexpensively available gas sensors as well as the accuracy and selectivity of detection. We would like to present a new air pollutant concentration and breakthrough system that allows portable measurement of extremely small amounts of unknown pollutants.

[Prior art literature]

[Non-patent literature]

(Non-patent Document 1) Non-dispersive infrared CO2 sensor for low power using an LED light source that can be combined with smart devices (The Journal of Korean Institute of Communications and Information Sciences '15-08 Vol.40 No.08)

(Non-patent Document 2) Quantitative analysis of volatile organic compounds in gas samples using solid-phase microextraction method (J. Kor. Soc. Environ. Eng., 35(12), 906~917, 2013)

The present invention includes a core formed of conductive fiber to enable portable measurement while detecting very small amounts of air pollutants with high accuracy and selectivity using a solid phase microextraction method; and a shell that is spun on the core to form a yarn structure, and the yarn is formed of adsorbent nanofibers. A core-shell structure that desorbs a very small amount of pollutants concentrated in the shell by self-heating of the core. The task is to provide a system for concentrating and breaking through air pollutants.

In order to achieve the above object, the present invention is a core-shell structured air pollutant concentration and breakthrough system, comprising: a core formed of conductive fiber; and a shell spun on the core to form a yarn structure, wherein the yarn is formed of adsorbent nanofibers.

In one embodiment, the conductive fiber may be made of one or more selected from carbon nanotubes, carbon black, silver, copper, aluminum, iron, zinc, nickel, polyacetylene, polyaniline, polypyrrole, and thiophene.

In one embodiment, the system may further include a power unit that supplies electrical energy to the core.

In one embodiment, the core generates heat by Joule heating to desorb air pollutants concentrated or adsorbed on the shell.

In one embodiment, the adsorptive nanofibers may further include particles with adsorptive properties inside and/or outside the adsorptive nanofibers. Preferably, the adsorptive nanofibers are made of polydimethylsiloxane (PDMS) or polyacrylate. , PA), Carbowax (CW)/divinylbenzene (DVB), Carbowax (CW)/templated resin (TPR), polydimethylsiloxane (PDMS)/divinylbenzene Choose between (divinylbenzene, DVB), Carboxen (CAR)/Polydimethylsiloxane (PDMS), and divinylbenzene (DVB)/Carboxen (CAR)/Polydimethylsiloxane (PDMS) It can be one or more of the following.

In addition, the present invention relates to a method for measuring air pollutants, comprising: a) preparing an air pollutant concentration and breakthrough system of a core of conductive fiber and a shell made of absorbent nanofibers with a yarn structure; b) adsorbing and concentrating air pollutants into the system; c) after a certain degree of concentration has been achieved in step b), passing electricity to the core fiber to desorb air pollutants by generating electrical heat; d) detecting the desorbed air pollutant using a detection device; providing a method for detecting an air pollutant, comprising:

In one embodiment, step b) may be performed while allowing atmospheric air to flow into the shell side of the enrichment and breakthrough system.

In one embodiment, the desorption in step c) may be performed while flowing a carrier gas.

In one embodiment, the detection device may be a portable detection sensor.

The system of the present invention is formed of a core-shell composite structure, wherein the shell is formed into a yarn structure by spinning adsorbent nanofibers, so that the size and volume of the voids between the nanofibers forming the yarn structure can be arbitrarily designed, By rapidly diffusing (moving) gas through pores formed by pores, very small amounts of air pollutants can be effectively adsorbed and concentrated.

In addition, the present invention self-heats by Joule heating when voltage is applied to the conductive fiber formed as a core, so the air pollutants adsorbed and concentrated on the shell can be desorbed (breakthrough) without an external heating device, making it portable. there is.

In addition, since the bonding of the core and shell is achieved by spinning adsorbent nanofibers into the core, additional processes such as separate binders or sintering are not required, thereby simplifying the manufacturing process.

Figure 1 shows an air pollutant concentration and breakthrough system according to an embodiment of the present invention.

Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. In general, the nomenclature used herein is well known and commonly used in the art.

Throughout this specification, when a part “includes” a certain element, this means that it may further include other elements rather than excluding other elements, unless specifically stated to the contrary. Hereinafter, the present invention will be described in detail.

In one aspect, the present invention is a core-shell structured air pollutant concentration and breakthrough system, comprising: a core formed of conductive fiber; and a shell spun on the core to form a yarn structure, wherein the yarn is formed of adsorbent nanofibers.

Figure 1 shows an air pollutant concentration and breakthrough system according to an embodiment of the present invention, which will be described in detail with reference to this.

In the present invention, the core is made of conductive fiber, and joule heating is possible.

Joule heating means that the passage of an electric current through an electrical conductor generates heat energy, and the core formed of the conductive fiber can self-heat when a voltage is applied, creating a pulse in response to the momentarily applied voltage. It allows for highly responsive temperature control.

Specifically, the conductive fiber is a material that can generate heat when voltage is applied, and is any material selected from carbon nanotubes, carbon black, silver, copper, aluminum, iron, zinc, nickel, polyacetylene, polyaniline, polypyrrole, and thiophene. It may be made of one or more carbon fibers, metal fibers, alloy wire oil, conductive polymer fibers, etc., but is not limited thereto, but preferably, the conductive fibers are conductive fibers capable of string heating below 300°C.

In addition, the conductive fiber is characterized in that it has a form that can be used free-standing during the pulling or rolling step in the yarn spinning process, and is preferably thick enough to be stably used in the yarn spinning process. It is characterized in that it has a structure that can be used as a core fiber for yarn spinning because it is in the form of a single fiber that can be used, or when it is thin, one-dimensional single fibers are formed in a bundle, or are twisted together.

The joule heating may be achieved by further including a power unit that supplies electrical energy to the core of the system.

In the present invention, the shell is formed of adsorptive nanofibers that are spun on the core to form a yarn structure, and the yarn structure is formed by spinning nanofibers with adsorptive properties on the core by spinning method, spinning direction, etc. By controlled spinning, nanofibers with adsorption properties can be formed into yarns that have a relatively regular orientation or are randomly entangled to form a three-dimensional structure.

Specifically, the yarn structure may be a structure in which adsorbent nanofibers form a certain direction and surround the conductive fiber, a structure in which two or more directions are mixed, or a three-dimensional structure in which the adsorbent nanofibers are randomly entangled with the conductive fiber. You can.

As an example, the yarn structure may be formed by spun nanofibers with adsorption properties on both sides around a core formed of conductive fibers capable of string heating, and a large amount of nanofibers are radiated through the fibers that make up the yarn structure and the macropores of the fibers. The gas diffuses (moves) quickly and can more easily adsorb air pollutants.

In the present invention, the spinning method is not limited, but preferably electrospinning, and the adsorbent nanofiber is a component that can selectively adsorb or absorb air pollutants, such as the component to be adsorbed/absorbed, ease of sample detachment, breakthrough point, etc. The types are not limited as they can be selected in consideration of the Wax (Carbowax, CW)/divinylbenzene (DVB), Carbowax (CW)/templated resin (TPR), Polydimethylsiloxane (PDMS)/divinylbenzene (DVB) , Carboxen (CAR)/Polydimethylsiloxane (PDMS), divinylbenzene (DVB)/Carboxen (CAR)/Polydimethylsiloxane (PDMS), one or more polymers selected from It could be material.

In addition, the adsorbent nanofiber may be one in which the material constituting the nanofiber acts as an adsorbent, or inserts or binds adsorbent particles of several nanometers to micrometers in size, which can act as an adsorbent on the outside and/or inside the adsorbent nanofiber. there is.

The adsorbent particles include magnetic nano-adsorbents, covalent organic frameworks (COFs), metal-organic frameworks (MOFs), hybrid nanosorbents, and molecularly imprinted materials. MIMs), fibers, nanofibers, silica-based nanosorbents, metal oxide nanosorbents, conductive polymers, amorphous silicate sediments, metal-organic nanotube-based composite sponges ( It may be one or more selected from metal-organic nanotube-based composite sponge, nanohydroxyapatite, and layered double hydroxides.

The air pollutant concentration and breakthrough system having a core-shell composite structure of the present invention adsorbs and concentrates air pollutants by a shell of a yarn structure formed by spinning the absorbent nanofibers, and then uses a core formed of the conductive fibers. By applying a voltage, the conductive fiber effectively breaks through (desorbs) air pollutants adsorbed and concentrated on the shell by self-heating.

Therefore, unlike the conventional solid-phase trace extraction method that detects air pollutants by GC/MS using external heat inside the chamber, the present invention is a method of detecting air pollutants by GC/MS, which is adsorbed and concentrated on the shell by self-heating of the core that makes up the system. Because it can break through (desorb) air pollutants, this system can be installed in front of existing low-cost sensors, provides accuracy and selectivity, and provides portability.

In addition, the air pollutant concentration and breakthrough system having a core-shell composite structure of the present invention forms a shell with a yarn structure by spinning adsorbent nanofibers on a core formed of conductive fibers capable of string heating, thereby forming a shell with a yarn structure. The manufacturing process is simple as it does not require additional processes such as binders and sintering to adhere.

Thereafter, the breakthrough (desorption) air pollutant is analyzed using a detection sensor, GC, or mass spectrometer to analyze the concentration and type of the air pollutant.

Additionally, the present invention provides a method for detecting air pollutants.

The method for detecting air pollutants according to the present invention includes the steps of a) preparing an air pollutant concentration and breakthrough system of a core of conductive fiber and a shell made of absorbent nanofibers with a yarn structure; b) adsorbing and concentrating air pollutants into the system; c) after a certain degree of concentration has been achieved in step b), passing electricity to the core fiber to desorb air pollutants by generating electrical heat; d) detecting the desorbed air pollutants using a detection device.

The air pollutant concentration and breakthrough system in step a) is the same as described above. The system includes the step of spinning nanofibers with adsorption properties on both sides around a core formed of conductive fibers. At this time, the spinning can be done using a conventional method, preferably electrospinning.

Step b) is a step in which air pollutants are adsorbed to the shell side of the air pollutant concentration and breakthrough system. At this time, the lower the temperature at the time of adsorption, the more advantageous it is, but usually it can be room temperature. The adsorption is intended to increase the concentration by concentrating the air pollutant when the concentration in the air is low and difficult to detect by general methods. The adsorption time may vary depending on the type of air pollutant and the concentration of the air pollutant in the air. . Alternatively, the adsorption time for concentration of the air pollutants can be reduced by allowing the air containing the air pollutants to flow to the shell side of the concentration and breakthrough system.

Step c) is a step to facilitate detection in step d) by breaking through (desorbing) the air pollutants adsorbed on the adsorbent and making the concentration higher than in the air. Therefore, for the breakthrough (desorption), it is advantageous to concentrate the air pollutants by instantly raising the temperature to the breakthrough (desorption) temperature. The conductive fiber according to the present invention is based on an electrical invention and has the advantage of enabling highly responsive temperature control in the form of a pulse by instantaneously applying voltage. In addition, the nanofibers that act as an adsorbent around the core of the conductive fiber form a yarn structure, allowing a large amount of gas to quickly diffuse through the fiber and its macropores not only when air pollutants are adsorbed but also when desorbed ( Since it can move, the response characteristics become even better. In step c), a carrier gas may be used to move the breakthrough (desorbed) air pollutant. The carrier gas is not limited, but an inert gas is preferably used. The breakthrough (desorption) temperature may vary depending on the type of air pollutant, but may typically be in the range of 50 to 300°C.

Step d) is the step of detecting air pollutants that have broken through (desorbed). The detection means can be any known type of sensor, preferably a portable detection sensor, for example, an electrochemical sensor, a semiconductor sensor, a solid electrolyte sensor, a photo ionization sensor, a total reflection sensor, or an optical sensor (non-electrochemical sensor). There are distributed infrared sensors, photoacoustic sensors, etc., but more preferably, a low-cost semiconductor sensor can be used as a real-time portable detection device to construct a popular air pollution source detection device.

As the specific parts of the present invention have been described in detail above, it is clear to those skilled in the art that these specific techniques are merely preferred embodiments and do not limit the scope of the present invention. will be. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (10)

A core-shell structured air pollutant concentration and breakthrough system, comprising: a core formed of conductive fiber; and An air pollutant concentration and penetration system comprising a shell formed of adsorbent nanofibers, wherein the yarn is spun on the core to form a yarn structure. According to paragraph 1, The conductive fiber is characterized in that it is made of one or more selected from carbon nanotubes, carbon black, silver, copper, aluminum, iron, zinc, nickel, polyacetylene, polyaniline, polypyrrole, and thiophene, and is capable of concentrating and breaking through air pollutants. system. According to paragraph 1, The system is an air pollutant concentration and breakthrough system, characterized in that it further includes a power unit that supplies electrical energy to the core. According to paragraph 1, An air pollutant concentration and breakthrough system, characterized in that the core generates heat by Joule heating to desorb air pollutants concentrated or adsorbed on the shell. According to paragraph 1, An air pollutant concentration and penetration system, characterized in that the adsorptive nanofibers may further include particles having adsorptive properties inside and/or outside the absorbent nanofibers. According to paragraph 1, The adsorbent nanofibers include polydimethylsiloxane (PDMS), polyacrylate (PA), Carbowax (CW)/divinylbenzene (DVB), Carbowax (CW)/template resin. (templated resin, TPR), Polydimethylsiloxane (PDMS)/divinylbenzene (DVB), Carboxen (CAR)/Polydimethylsiloxane (PDMS), divinylbenzene (DVB) / Carboxen (CAR) / Polydimethylsiloxane (PDMS), an air pollutant concentration and penetration system characterized in that it is one or more selected from the group. In the method of measuring air pollution sources, a) preparing an air pollutant concentration and breakthrough system of a shell composed of a conductive fiber core and yarn-structured adsorbent nanofibers; b) adsorbing and concentrating air pollutants into the system; c) after a certain degree of concentration has been achieved in step b), passing electricity to the core fiber to desorb air pollutants by generating electrical heat; d) detecting the desorbed air pollutant using a detection device; a method for detecting an air pollutant, comprising: In clause 7, Step b) is performed while allowing the atmosphere to flow to the shell side of the concentration and breakthrough system. In clause 7, A method for detecting air pollutants, characterized in that the desorption in step c) is performed while flowing a carrier gas. In clause 7, A method for detecting air pollutants, wherein the detection device is a portable detection sensor.

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