KR20240060105A - Colorimetric sensors with ruthenium compound anchored nanofibers and manufacturing mtehod thereof - Google Patents

Abstract

The present invention relates to a color change gas sensor using nanofibers bound with a ruthenium compound and a method of manufacturing the same. More specifically, a color change gas sensor with improved sensor responsiveness due to a large gas reaction surface area by forming a nanofiber membrane and the same. It is about manufacturing method. The color change gas sensor of the present invention forms a nanofiber membrane with nanofibers bound to a ruthenium compound, thereby improving the responsiveness of the sensor with a large gas reaction surface area.

Description

Color change gas sensor using nanofibers bound with ruthenium compound and manufacturing method thereof {COLORIMETRIC SENSORS WITH RUTHENIUM COMPOUND ANCHORED NANOFIBERS AND MANUFACTURING MTEHOD THEREOF}

The present invention relates to a color change gas sensor using nanofibers bound with a ruthenium compound and a method of manufacturing the same. More specifically, a color change gas sensor with improved sensor responsiveness due to a large gas reaction surface area by forming a nanofiber membrane and the same. It is about manufacturing method.

Gas sensors are used throughout society, and in industrial companies, they can prevent major accidents or casualties by early determining the leakage of harmful gases through hazardous environmental gas alarms. In close proximity to real life, they are used as air pollution level meters or indoor air quality meters. It serves to provide a comfortable environment by monitoring the overall air quality of the living space.

There are various gas sensors depending on the gas detection operation method, such as gas chromatography, resistance change gas sensor, and color change sensor. In gas chromatography, vaporization occurs when a sample is injected into the inlet, and gaseous substances are separated by columns in the gas chromatography. The separated gaseous compound components are detected by the detector and an electrical signal proportional to the detected amount is displayed through a connected monitor. Compared to other gas sensors, gas chromatography is capable of very accurate quantitative gas analysis, but it is expensive and the size of the equipment is large, so it is not suitable as a portable device. Additionally, since the sample must be vaporized at the same time as it is injected, the sample must have volatile characteristics. Therefore, the molecular weight of the sample that can be analyzed is limited, and materials that are not stable to heat have the disadvantage of being difficult to analyze.

A resistance change gas sensor based on a metal oxide semiconductor detects the gas of interest (analyte) using the change in electrical resistance that occurs during the process of adsorption and desorption of a specific gas on the surface of a metal oxide semiconductor. Gas sensors based on metal oxide semiconductors can quantitatively detect specific gases by analyzing the ratio of resistance in a specific gas to that in air. These resistance-variable gas sensors have the advantage of being easy to configure the sensor system and easy to carry due to their small size. However, because it lags far behind gas chromatography in terms of sensitivity and selectivity, much research is still being done. In addition to gas chromatography and metal oxide semiconductor-based gas sensors, research on colorimetric sensors, which can observe color changes with the naked eye by reacting with a specific gas, is also being actively conducted.

In a color change gas sensor, the material used as a dye in the gas sensor reacts with the analyte gas, and the absorption wavelength for visible light changes due to the band gap, which is an electrical property. As a result, the complementary color of the actually visible absorption wavelength changes. This causes color transfer that can be seen with the naked eye. Alternatively, through a chemical reaction that occurs when a specific gas comes into contact with a dye, a colored product different from the color of the raw material is formed, making it possible to determine the presence or absence of the analyte gas. Gas sensors using color-changing materials have the advantage of not requiring additional circuit design and measurement equipment compared to gas sensors based on metal oxide semiconductors because color transitions can be distinguished with the naked eye. In addition, since it can be easily carried around in the form of a test strip, gas can be monitored or detected in real time regardless of time and place. However, gas sensitivity characteristics and selectivity are significantly inferior to gas chromatography and resistance change gas sensors.

In order to manufacture a color change sensor with high sensitivity performance, it is necessary to develop a color change sensor material with a large surface area to provide a large number of reaction areas where the analyte gas can meet. In the case of thick film type color change sensors, most reactions occur on the surface of the film, and the absence of pores prevents gas molecules from diffusing into the sensing material, resulting in relatively limited reactions. Therefore, the development of a color change sensor material with a porous structure that allows gas molecules to diffuse into the sensing material is also necessary. In addition, when color-changing dyes are bound to the inside of a nanostructure, there is a limit to the diffusion of the reaction gas into the material forming the nanostructure, so a reaction with the gas of interest (analyte) cannot be induced. Therefore, it is important to distribute the dye on the surface of the nanostructure so that it meets the reaction gas and causes color transfer.

Republic of Korea Patent Publication No. 10-2342441 (2021.12.20)

The present invention is intended to solve the above problems and relates to a color change gas sensor in which the reactivity of the sensor is improved by forming a nanofiber membrane with nanofibers bound with a ruthenium compound, thereby improving the sensor's responsiveness with a large gas reaction surface area.

In addition, the present invention provides a method for simply manufacturing a nanofiber membrane into a desired shape using electrospinning.

According to one aspect of the present invention, a ruthenium compound represented by the following formula (1) includes a nanofiber membrane bound to a polymer having a nanometer-sized fiber structure, and the ruthenium compound reacts with carbon monoxide (CO) gas molecules. A nanofiber membrane color change sensor that changes color through exposure is provided.

[Formula 1]

Here, R is pyrenyl, phenanthrenyl, naphthyl, -Nap-2-OMe-6, -C ₆ H ₄ Me-4, or -C ₆ H ₅ .

The nanofiber membrane may change color through reaction with carbon monoxide (CO) gas molecules when the ruthenium compound is exposed to the inner and outer surfaces of the nanofiber.

The nanofiber membrane is dispersed in the solvent in a state in which the ruthenium compound is not dissolved in the solvent used in the production of nanofibers, so that the ruthenium compound penetrates the inside and outside of the nanofiber during the process of producing the nanofiber. When exposed to the surface, the color may change through reaction with the gas molecules.

Depending on the reaction between carbon monoxide gas and the ruthenium compound, the color may change as the 2,1,3-Benzothiadiazole (BTD) ligand contained in the ruthenium compound is replaced with carbon monoxide.

In order to form a nanofiber membrane without detachment of the ruthenium compound, the ruthenium compound may be bound to the interior and surface of the polymer nanofiber obtained through electrospinning.

The diameter of the polymer nanofibers included in the nanofiber membrane may be 50 nm to 5 μm.

The weight ratio of the ruthenium compound in the nanofiber membrane may be 1 to 10 wt% relative to the polymer.

According to another aspect of the present invention, (a) dissolving a polymer in a solvent to prepare a polymer solution; (b) preparing an electrospinning solution by dispersing a ruthenium compound represented by the following formula (1) in the polymer solution; (c) binding the polymer and the ruthenium compound to each other using the electrospinning method using the electrospinning solution, forming nanofibers in which the ruthenium compound remains uniformly inside and on the surface; and (d) forming a nanofiber membrane by directly spinning the nanofibers formed by the electrospinning method on a substrate.

[Formula 1]

Here, R is pyrenyl, phenanthrenyl, naphthyl, -Nap-2-OMe-6, -C ₆ H ₄ Me-4, or -C ₆ H ₅ .

The polymer includes polycaprolactone (PCL), polymethyl acrylate (PMA), polyvinyl acetate (PVAc), polymethyl methacrylate (PMMA), polyacrylic copolymer, Polyvinyl acetate copolymer, polyfurfuryl alcohol (PPFA), polystyrene (PS, polystyrene), polyvinylpyrrolidone (PVP, Polyvinylpyrrolidone), polystyrene copolymer, polyacrylonitrile (PAN, Polyacrylonitrile), polycarbonate ( PC), polyurethane, polyurethane copolymer, polyvinyl chloride (PVC), polycaprolactone (PCL), polyvinyl fluoride, polyvinylidene fluoride copolymer, polyimide, styl At least one selected from styrene-acrylonitrile (SAN), polycarbonate (PC), polyethylene (PE), polyethylene terephthalate (PET), and polypropylene (PP) It can be.

The solvent is chloroform, dimethylformamide (DMF), acetone, tetrahydrofuran, toluene, dimethylacetamide (DMAc), and dimethyl sulfoxide (DMSO, dimethyl It may be one or more types selected from sulfoxide).

The polymer concentration of the polymer solution may be 10 to 20 wt%.

The weight ratio of the ruthenium compound to the polymer solution may be 1 to 10 wt%.

The electrospinning method may be performed at a pump rate of 0.1 to 1 mL/hr.

The electrospinning method may be performed by applying a voltage of 5 to 20 kV.

The distance between the substrate and the needle from which the nanofibers are spun may be 10 to 20 cm.

The thickness of the nanofiber membrane may be 10 μm to 200 μm.

The color change gas sensor of the present invention forms a nanofiber membrane with nanofibers bound to a ruthenium compound, thereby improving the responsiveness of the sensor with a large gas reaction surface area.

The manufacturing method of the color change gas sensor of the present invention can simply manufacture a nanofiber membrane into a desired shape using an electrospinning method.

Figure 1 is a photograph confirming that the color change gas sensor manufactured according to the example changes color in response to CO.
Figure 2 is a measurement of the change in RGB values according to the reaction time with CO of the color change gas sensor manufactured according to the example.

Hereinafter, the present invention will be described in detail. In describing the present invention, detailed descriptions of related known structures or functions may be omitted.

Terms or words used in this specification and patent claims should not be construed as limited to their usual or dictionary meanings, but should be construed with meanings and concepts consistent with the technical details of the present invention.

The embodiments described in this specification and the configurations shown in the drawings are preferred embodiments of the present invention, and do not represent the entire technical idea of the present invention, so various equivalents and modifications that can replace them at the time of filing the present application are available. There may be.

Hereinafter, the color change sensor of the present invention will be described in detail.

The nanofiber membrane color change sensor of the present invention includes a nanofiber membrane in which a ruthenium compound represented by the following formula (1) is bound to a polymer having a nanometer-sized fiber structure, and the ruthenium compound interacts with carbon monoxide (CO) gas molecules. The color changes through the reaction.

[Formula 1]

Here, R is pyrenyl, phenanthrenyl, naphthyl, -Nap-2-OMe-6, -C ₆ H ₄ Me-4, or -C ₆ H ₅ .

The pyrenyl group, phenanthrenyl group, naphthyl group, -Nap-2-OMe-6, -C ₆ H ₄ Me-4 and -C ₆ H ₅ are represented by the following formula (2) It can be.

[Formula 2]

The nanofiber membrane may change color through reaction with carbon monoxide (CO) gas molecules when the ruthenium compound is exposed to the inner and outer surfaces of the nanofiber.

The nanofiber membrane is dispersed in the solvent in a state in which the ruthenium compound is not dissolved in the solvent used in the production of nanofibers, so that the ruthenium compound penetrates the inside and outside of the nanofiber during the process of producing the nanofiber. When exposed to the surface, the color may change through reaction with the gas molecules.

Depending on the reaction between carbon monoxide gas and the ruthenium compound, the color may change as the 2,1,3-Benzothiadiazole (BTD) ligand contained in the ruthenium compound is replaced with carbon monoxide.

Specifically, looking at the reaction mechanism between the ruthenium compound (1) and carbon monoxide gas disclosed in Chemical Formula 3 below according to an embodiment of the present invention, the 2,1,3-Benzothiadiazole (BTD) ligand constituting the chemical structure of the ruthenium compound is Although it is structurally well balanced, it is highly unstable and can be easily replaced by a better donor. The BTD ligand is easily replaced by a carbon monoxide molecule in environmental conditions where carbon monoxide gas is present, and at this time, the luminescence of the functional group (here, pyrenyl group) suppressed by the action of BTD is restored, causing a unique discoloration.

[Formula 3]

The fiber structure may include a one-dimensional shape.

In order to form a nanofiber membrane without detachment of the ruthenium compound, the ruthenium compound may be bound to the interior and surface of the polymer nanofiber obtained through electrospinning.

The diameter of the polymer nanofibers included in the nanofiber membrane may be 50 nm to 5 μm.

The size of the ruthenium compound is preferably smaller than the diameter of the polymer nanofiber. The average diameter of the ruthenium compound may be in the range of 1 nm to 1 μm.

The weight ratio of the ruthenium compound in the nanofiber membrane may be 1 to 10 wt% relative to the polymer. When the weight ratio of the ruthenium compound is less than 1 wt%, sensor responsiveness is reduced, and when it exceeds 10 wt%, it is difficult to maintain the shape of the nanofiber membrane.

Hereinafter, the manufacturing method of the nanofiber membrane color change sensor of the present invention will be described in detail.

First, prepare a polymer solution by dissolving the polymer in a solvent (step a).

The polymer includes polycaprolactone (PCL), polymethyl acrylate (PMA), polyvinyl acetate (PVAc), polymethyl methacrylate (PMMA), polyacrylic copolymer, Polyvinyl acetate copolymer, polyfurfuryl alcohol (PPFA), polystyrene (PS, polystyrene), polyvinylpyrrolidone (PVP, Polyvinylpyrrolidone), polystyrene copolymer, polyacrylonitrile (PAN, Polyacrylonitrile), polycarbonate ( PC), polyurethane, polyurethane copolymer, polyvinyl chloride (PVC), polycaprolactone (PCL), polyvinyl fluoride, polyvinylidene fluoride copolymer, polyimide, styl It may be styrene-acrylonitrile (SAN), polycarbonate (PC), polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), etc.

The solvent is chloroform, dimethylformamide (DMF), acetone, tetrahydrofuran, toluene, dimethylacetamide (DMAc), and dimethyl sulfoxide (DMSO, dimethyl sulfoxide), etc.

The polymer concentration of the polymer solution may be 10 to 20 wt%. If the polymer concentration is less than 10 wt%, the polymer solution flows like water and is difficult to spin, and if it exceeds 20 wt%, the viscosity is too high, making it difficult to spin through a needle.

Next, an electrospinning solution is prepared by dispersing a ruthenium compound represented by the following formula (1) in the polymer solution (step b).

[Formula 1]

Here, R is pyrenyl, phenanthrenyl, naphthyl, -Nap-2-OMe-6, -C ₆ H ₄ Me-4, or -C ₆ H ₅ .

The weight ratio of the ruthenium compound to the polymer solution may be 1 to 10 wt%. If the weight ratio of the ruthenium compound is less than 1 wt%, sensor responsiveness is reduced, and if it exceeds 10 wt%, it is difficult to maintain the shape of the nanofibers constituting the nanofiber membrane. Since the ruthenium compound is not completely diluted in the solvent, it remains as large particles, and as a result, the needle may be clogged during electrospinning or the ruthenium compound particles aggregated on the surface of the formed nanofiber may appear in the form of spots.

Next, the polymer and the ruthenium compound bind together using the electrospinning method using the electrospinning solution, forming nanofibers in which the ruthenium compound remains uniformly on the inside and surface (step c).

The electrospinning method may be performed at a pump rate of 0.1 to 1 mL/hr. If the pump speed is less than 0.1 mL/hr, the thickness of the nanofiber may become too thin, and if it exceeds 1 mL/hr, the nanofiber may become thick.

The electrospinning method may be performed by applying a voltage of 5 to 20 kV. If the voltage is less than 5kV, the spinning of nanofibers to the substrate cannot be performed properly in the step described later, and if it exceeds 20kV, the spray shape becomes unstable and fine sparks may occur, which is dangerous.

Finally, the nanofibers formed by the electrospinning method are directly spun on the substrate to form a nanofiber membrane (step d).

The distance between the substrate and the needle from which the nanofibers are spun may be 10 to 20 cm. If the distance between the substrate and the needle is less than 10 cm, the thickness of the nanofiber becomes thicker, and the space between the nanofibers becomes closer, so that the gas reaction surface area of the nanofiber membrane may become too small, and exceeds 20 cm. In this case, the spinning process becomes unstable, making it difficult to control it to the desired shape.

The thickness of the nanofiber membrane may be 10 μm to 200 μm. If the thickness is less than 10 μm, it is difficult to manipulate with human hands after manufacturing, and if it exceeds 200 μm, the size of the sensor may become too large.

[Example]

Hereinafter, the present invention will be described with reference to preferred embodiments. However, this is for illustrative purposes only and does not limit the scope of the present invention.

Example: Manufacturing of color change gas sensor

The polymer Polycaprolactone (PCL) was dissolved in chloroform solvent to prepare a 13 wt% polymer mixed solution, and Ruthenium(II) complex (STREM chemicals, INC., 2,1,3-benzothiadiazole-kN1)carbonylchloro[(1E) was added to it. )-2-(1-pyrenyl)ethenyl]bis(triphenylphosphine)ruthenium(Ⅱ)) was added and stirred until sufficiently mixed to prepare an electrospinning solution.

The prepared electrospinning solution was mounted on the electrospinning equipment, the distance between the needle and the substrate on which the fibers were to be spun was adjusted to 15 cm, and electrospinning was performed by applying a contact pressure of 12 kV at a pump rate of 0.3 mL/hr. Specifically, a thin conductive packaging film made of aluminum was placed on the steel substrate of the electrospinning equipment, and electrospinning liquid was sprayed on it and separated after spinning for 3 to 4 hours to produce a color change gas sensor.

[Test example]

Test Example 1: Confirmation of color change due to CO reaction of color change gas sensor

Figure 1 is a photograph confirming that the color change gas sensor manufactured according to the example changes color in response to CO. Specifically, after placing and fixing the color change gas sensor manufactured according to the example in a chamber made of transparent acrylic, 600 ppm CO gas collected from a CO cylinder was injected into the chamber in a vacuum to discolor the color change gas sensor. was confirmed.

Referring to Figure 1, it was confirmed that the color changed from light brown to light yellow due to reaction with CO.

Test Example 2: Change in RGB values for CO response of color change gas sensor

Figure 2 is a measurement of the change in RGB values according to the reaction time with CO of the color change gas sensor manufactured according to the example. Specifically, 600 ppm of CO gas was injected into a transparent acrylic vacuum chamber where the color change gas sensor was fixed, and the color change process was filmed in real time. In addition, the RGB values of the color displayed by the color change gas sensor in the video were extracted at specific time intervals.

Referring to Figure 2, it was confirmed that discoloration was induced within a short time of 50 seconds after reaction with CO gas.

Claims (16)

It includes a nanofiber membrane in which a ruthenium compound represented by the following formula (1) is bound to a polymer having a nanometer-sized fiber structure,
The color of the ruthenium compound changes through reaction with carbon monoxide (CO) gas molecules,
Nanofiber membrane color change sensor.

[Formula 1]

Here, R is pyrenyl, phenanthrenyl, naphthyl, -Nap-2-OMe-6, -C ₆ H ₄ Me-4, or -C ₆ H ₅ .
According to paragraph 1,
The nanofiber membrane color change sensor is characterized in that the ruthenium compound is exposed to the inner and outer surfaces of the nanofiber and changes color through reaction with carbon monoxide (CO) gas molecules.
According to paragraph 1,
The nanofiber membrane is dispersed in the solvent in a state in which the ruthenium compound is not dissolved in the solvent used in the production of nanofibers, so that the ruthenium compound penetrates the inside and outside of the nanofiber during the process of producing the nanofiber. A nanofiber membrane color change sensor that is exposed to the surface and changes color through reaction with the gas molecules.
According to paragraph 1,
A nanofiber membrane color change sensor characterized in that the color changes as the 2,1,3-Benzothiadiazole (BTD) ligand contained in the ruthenium compound is replaced with carbon monoxide according to the reaction between carbon monoxide gas and the ruthenium compound.
According to paragraph 1,
A nanofiber membrane color change sensor, characterized in that the ruthenium compound is bound to the interior and surface of a polymer nanofiber obtained through electrospinning in order to form a nanofiber membrane without desorption of the ruthenium compound.
According to paragraph 1,
A nanofiber membrane color change sensor, characterized in that the diameter of the polymer nanofibers included in the nanofiber membrane is 50 nm to 5 μm.
According to paragraph 1,
A nanofiber membrane color change sensor, characterized in that the weight ratio of the ruthenium compound in the nanofiber membrane is within a concentration range of 1 to 10 wt% relative to the polymer.
(a) preparing a polymer solution by dissolving the polymer in a solvent;
(b) preparing an electrospinning solution by dispersing a ruthenium compound represented by the following formula (1) in the polymer solution;
(c) binding the polymer and the ruthenium compound to each other using the electrospinning method using the electrospinning solution, forming nanofibers in which the ruthenium compound remains uniformly inside and on the surface;
(d) forming a nanofiber membrane by directly spinning the nanofibers formed by the electrospinning method onto a substrate;
Method for manufacturing a nanofiber membrane color change sensor comprising.

[Formula 1]

Here, R is pyrenyl, phenanthrenyl, naphthyl, -Nap-2-OMe-6, -C ₆ H ₄ Me-4, or -C ₆ H ₅ .
According to clause 8,
The polymer includes polycaprolactone (PCL), polymethyl acrylate (PMA), polyvinyl acetate (PVAc), polymethyl methacrylate (PMMA), polyacrylic copolymer, Polyvinyl acetate copolymer, polyfurfuryl alcohol (PPFA), polystyrene (PS, polystyrene), polyvinylpyrrolidone (PVP, Polyvinylpyrrolidone), polystyrene copolymer, polyacrylonitrile (PAN, Polyacrylonitrile), polycarbonate ( PC), polyurethane, polyurethane copolymer, polyvinyl chloride (PVC), polycaprolactone (PCL), polyvinyl fluoride, polyvinylidene fluoride copolymer, polyimide, stye At least one type selected from styrene-acrylonitrile (SAN), polycarbonate (PC), polyethylene (PE), polyethylene terephthalate (PET), and polypropylene (PP) A method of manufacturing a nanofiber membrane color change sensor, characterized in that.
According to clause 8,
The solvent is chloroform, dimethylformamide (DMF), acetone, tetrahydrofuran, toluene, dimethylacetamide (DMAc), and dimethyl sulfoxide (DMSO, dimethyl A method of manufacturing a nanofiber membrane color change sensor, characterized in that one or more types selected from sulfoxide).
The method of claim 8, wherein in step (a),
A method of manufacturing a nanofiber membrane color change sensor, characterized in that the polymer concentration of the polymer solution is 10 to 20 wt%.
The method of claim 8, wherein in step (b),
A method of manufacturing a nanofiber membrane color change sensor, characterized in that the weight ratio of the ruthenium compound to the polymer solution is 1 to 10 wt%.
9. The method of claim 8, wherein in step (c) or (d),
A method of manufacturing a nanofiber membrane color change sensor, characterized in that the electrospinning method is performed at a pump rate of 0.1 to 1 mL/hr.
14. The method of claim 13, wherein in step (c) or (d),
A method of manufacturing a nanofiber membrane color change sensor, characterized in that the electrospinning method is performed by applying a voltage of 5 to 20 kV.
The method of claim 8, wherein in step (d),
A method of manufacturing a nanofiber membrane color change sensor, characterized in that the distance between the substrate and the needle from which the nanofibers are spun is 10 to 20cm.
The method of claim 8, wherein in step (d),
A method of manufacturing a nanofiber membrane color change sensor, characterized in that the thickness of the nanofiber membrane is 10 μm to 200 μm.