KR20180119086A - Colorimetric gas sensors with hydrohpilic particles and color change dye anchored one dimensional nanofiber membrane and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a composite polymeric nanofiber membrane colorimetric sensor for gas indication in which hydrophilic particles and a colorimetric dye material are bonded to a one-dimensional nanofiber structure, and a production method thereof. To this end, the composite polymeric nanofiber membrane colorimetric sensor is composed of polymeric nanofibers in which hydrophilic particles inducing moisture adsorption in the air and the colorimetric dye material changing colors in reaction to specific gas molecules are bonded. In addition, the hydrophilic particles adsorb moisture in the air to increase the reactivity between the gas molecules and the colorimetric dye material, thereby greatly increasing the color change sensitivity.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a color-change sensor for a gas-indicating complex polymer nanofiber membrane in which a hydrophilic particle and a color-changing dye material are bonded to a one-dimensional nanofiber structure and a manufacturing method thereof. BACKGROUND ART THEREOF}

The present invention relates to a color filter comprising a color change dye material which reacts with a specific gas molecule to cause color change and a hydrophilic particle which absorbs moisture well and is uniformly bound to a one-dimensional nanofiber, The present invention relates to a polymer nanofiber membrane color sensor and a method of manufacturing the same. Specifically, the present invention provides nanofibers in which hydrophilic particles and color-changing dye materials are uniformly bonded to the inside and the surface of polymer nanofibers using an electrospinning process. Using a porous structure with high specific surface area and gas diffusion of nanofibers, the color change dye material binds to the nanofibers uniformly to maximize the area of the color change dye material exposed to air. In addition, hydrophilic particles bind to nanofibers to adsorb moisture in the air to promote the reaction between gas molecules and color-changing dye materials, as well as effectively exposing color-changing dye materials to air, thereby achieving excellent color change performance with a minimum amount of dye The present invention relates to a color change gas sensor having a hydrophilic particle and a color change dye material bound thereto, and a method for manufacturing the same.

A gas sensor is a detection device used to measure the concentration of a specific gas molecule in the atmosphere. In a factory, it can detect a leak of a harmful gas early to prevent a great accident or personal injury. In real life, Measuring the quality of life.

Commonly used gas sensors include gas chromatography, resistance-changing gas sensors, and color change gas sensors. Each sensor has its advantages and disadvantages and is limited in its purpose or environment.

Gas chromatography is capable of highly accurate qualitative and quantitative analysis compared to other gas sensors, but it has the disadvantage that the equipment is expensive, the equipment size is large, and the analysis time is long.

Resistive gas sensors use metal oxide based semiconductor materials to measure the presence and concentration of specific gas molecules. The amount of electric resistance which is changed in the course of adsorption and desorption of the target gas on the surface of the metal oxide semiconductor is measured to carry out the quantitative and qualitative analysis of the target gas. The resistance change type gas sensor is advantageous in that the configuration of the sensor system is simple and the size is small and the portability is high as compared with other gas sensors. However, the types of gas that can be measured are limited, and the sensitivity is lower than that of gas chromatography. Particularly, in the case of gases having a concentration of 1 ppm or less, it is difficult to measure with the resistance change type gas sensor.

The color change gas sensor is based on the principle that the color of a dye material exposed to a gas through adsorption and chemical reaction of a specific gas molecule and a color change dye material is changed. Particularly, the color change gas sensor is advantageous in that the presence and concentration of a specific gas molecule can be easily observed and measured even by the naked eye, a special electric device is not required, a light and small size can be obtained, and a measurement time is relatively short. However, since the detection concentration limit is significantly higher than that of other gas sensors and the gas selectivity is not excellent, studies on color change gas sensors have been actively carried out in order to improve them.

Recently, gas sensors have been actively applied to the healthcare field by detecting biomarker gas from the human body and diagnosing a specific disease or being used as an apparatus capable of monitoring early. When a person is suffering from a specific disease, they make new biomarkers in the body or produce more of the existing biomarkers, and the created biomarkers are excreted through the lungs. A variety of biological surface gases such as hydrogen sulfide, acetone, toluene, nitrogen monoxide, ammonia and pentane exist in human exhalation, and these gases are reported as biomarkers for halitosis, lung cancer, diabetes, kidney disease, kidney disease and asthma have. Because the exhalation contains hundreds of different kinds of gases, a sensing material with excellent selectivity that can selectively detect only a specific biochemical surface gas is needed. In addition, since the concentration of the biomarker gas contained in the exhalation is extremely small from 10 ppb (parts per billion) to about 10 ppm (part per million), the gas sensor for disease diagnosis requires high sensitivity.

The color change gas sensor for health care also requires the same high gas selectivity and high sensitivity. In the color change gas sensor, since the specific gas molecules cause a color change through a surface chemical reaction with the color change dye material, the sensitivity of the color change sensor can be increased by maximizing the exposed area of the color change dye material in the air. Thus, nanostructured materials with high surface area and porosity have better sensitivity to color change sensors than simple film-type materials, and the detection rate is also relatively fast because gas molecules can diffuse quickly to the deep part of the sensing material.

As an example of the color change gas sensor, a hydrogen sulfide (H ₂ S) gas-indicating color change sensor is commercialized and commercially available. Hydrogen sulfide gas is a biomarker of halitosis and contains hydrogen sulfide gas in the range of about 50 ppb to 80 ppb for normal person's exhalation, while hydrogen sulfide gas is contained in about 1 ppm to 2 ppm for halitosis patient's exhalation. Lead (II) acetate is widely known as a color change dye material capable of selectively sensing hydrogen sulfide gas. Although hydrogen sulfide gas sensing film for industrial use has been commercialized in the market, since the limit of detection is as high as 5 ppm, it is difficult to apply to various fields. Especially, since it is used as a color change gas sensor for healthcare, It is too low.

In order to manufacture a high-sensitivity color change sensor, it is necessary to develop a nano-structured color change sensor material so that the color change dye material expands the surface area exposed to the air as much as possible and has a reaction site. In the case of a simple film sensor, the chemical reaction occurs only on the color change dye material on the film surface, and the color change dye material inside the film can not participate in the reaction, resulting in a loss of efficiency and sensitivity. Therefore, it is necessary to develop a color change sensor material having a porous structure that allows gas molecules to diffuse into the sensing material and perform a surface chemical reaction with the internal color change dyes.

In order to further increase the sensitivity of the color change sensor, there is a need for a technique for creating an optimal environment for increasing the reactivity between the specific gas molecule to be detected and the color change dye material. One of the methods for making the environment is to make the nanofiber hydrophilic or hydrophobic so that the specific gas molecules are adsorbed to the nanofibers better. In the case of a gas such as hydrogen sulfide, a method of maximizing the sensitivity of color change by promoting the reactivity with hydrogen sulfide by introducing a hydrophilic group into the color change sensing material is required because it has a property of adsorbing to a hydrophilic surface more effectively.

An object of the present invention is to provide a color change dye material which adsorbs and reacts with a specific gas molecule to cause a color change, is not desorbed from a product in use, maximizes an area exposed to air, The present invention also provides a method of manufacturing the same.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a polymer nanofiber membrane, which is characterized in that a hydrophilic particle and a color change dye material are bound together in a 1-dimensional nanofiber structure, To provide a method to do so.

As the hydrophilic particles and the color change dye material are bonded to the inside and the surface of the nanofiber, the surface roughness is increased, thereby maximizing the area of the color change dye material exposed to the air and introducing the hydrophilic group on the surface of the polymer nanofiber, And it is an object of the present invention to provide a color change gas sensor capable of detecting a very small amount of specific gas molecules even with a dye material, and a method of manufacturing the same.

According to an aspect of the present invention, there is provided a method for producing an electrodeposition solution, which comprises adding a hydrophilic particle and a color change dye material to a polymer solution in which a polymer is dissolved in a solvent to prepare an electric spinning solution, stirring the electrodeposition solution at a high temperature The color change dye material is re-precipitated as microcrystals through a rapid cooling process, thereby making the electrodeposited liquid dispersed. The electrospinning solution was synthesized and collected by using electrospinning process so that the hydrophilic particles and the color-changing dye material were uniformly bound to each other, and the complex polymer nanofiber membrane colored with the gas-indicating hydrophilic particles and the color- A method of manufacturing a change sensor is provided.

The gas-indicating composite polymer nanofiber membrane color sensor according to the present invention and the method for manufacturing a member for a color change sensor using the same may be divided into two. The method (1) comprises: (a) preparing an electrospinning solution by adding a hydrophilic particle and a color change dye material to a polymer solution in which a polymer is dissolved in a solvent; (b) fabricating a complex polymer nanofiber in which a one-dimensional hydrophilic particle and a color-changing dye material are bound using an electrospinning process; (c) collecting the composite polymer nanofibers in which the radiated hydrophilic particles and the color-changing dye material are bound in a nonwoven fabric in the form of a membrane. The method (2) comprises: (a) preparing an electrospinning solution by adding a hydrophilic particle and a color-changing dye material to a polymer solution in which a polymer is dissolved in a solvent; (b) dissolving the color-changing dye material in the electric spinning solution through a high-temperature stirring process; (c) preparing an electric spinning solution containing the dye and the hydrophilic particles solidified into microcrystals through a quenching process; (d) preparing a composite polymer nanofiber in which one-dimensional hydrophilic particles and color-changing dye material are bound using an electrospinning process; (e) collecting the conjugated polymer nanofibers in which the radiated hydrophilic particles and the color-changing dye material are bound in a nonwoven fabric in the form of a membrane.

In step (a) of the method 1 and method 2, a hydrophilic particle and a color-changing dye material are added to a polymer solution in which the polymer is dissolved to prepare an electrospinning liquid. Specifically, the polymer is a polyperfuryl alcohol (PPFA) , Polymethyl methacrylate (PMMA), polyacrylic copolymer, polyvinyl acetate (PVAc), polyvinyl acetate copolymer, polystyrene (PS), polyvinylpyrrolidone (PVP) ), Polystyrene copolymers, polyethylene oxide (PEO), polyethylene oxide copolymers, polycarbonate (PC), polyvinyl chloride (PVC), polypropylene oxide copolymers, polycaprolactone, Rid, polyvinylidene fluoride (PVDF), polyvinylidene fluoride copolymer, polyimide, polyvinylidene fluoride, Polyacrylonitrile, polyethylene terephthalate (PET), polypropylene oxide (PPO), polyvinyl alcohol (PVA), styrene acrylonitrile (SAN), acrylonitrile a mixture of at least one selected from the group consisting of ptyrene-acrylonitrile, polycarbonate (PC), polyaniline (PANI), polypropylene (PP) and polyethylene (PE)

The polymer constituting the electric spinning solution can be produced in a specific solvent in a weight ratio ranging from 0.1 to 90 wt%. In the electrospinning solution, the solvent is selected from the group consisting of water (deionized water), tetrahydrofuran, methanol, isopropanol, formic acid, acetonitrile, nitromethane ), Acetic acid, ethanol, acetone, ethylene glycol (EG), dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide DMAc, dimethylacetamide), and toluene.

The hydrophilic particles and the color-changing dye material are added in the form of particles having a size range of 2 nm to 300 nm and 1 nm to 1 μm, respectively, and the weight ratio of the hydrophilic particles to the color-changing dye material is May be selected in a concentration range of 0.1 to 100 wt% and 0.1 to 400 wt%, respectively. The color changing dyes may be selected from the group consisting of ball-milling, jaw crusher, gyratory crusher, hammer mill, corn mill, roll crusher, a screw mill, an edge runner, a ring-roll mill, a stamp mill, a rod mill, an impact pulverizer, a jet mill, A pulverizer, a colloid mill, a sonication, or the like.

In the step (b) of the method 2, the coloring dye material is selectively dissolved by heating the electrorheological fluid prepared in the step (a), and the heating temperature is heated to the melting point of the color changing dye material . It is possible to prepare a spinning solution containing the hydrophilic particles in which the color-changing dye material is dissolved by adding the color-changing dye material into the polymer solution in which the hydrophilic particles are dispersed and heating the mixture at a temperature higher than the melting point of the color-changing dye. When the heating temperature exceeds 150 ° C, the polymer may be deformed or decomposed, and the heating temperature is preferably selected within the range of 50 to 150 ° C, and the color changing dye material capable of melting in the temperature range is used .

In step (c) of the method 2, the electrospinning solution prepared in the step (b) is quenched to a temperature of 25 ° C or lower to recrystallize fine color-changing dye materials in and on the surface of the electrospinning liquid . Since the color-changing dye material dissolved in the polymer spinning solution through the high-temperature heating process can be re-precipitated into small particles through rapid cooling process and recrystallization is performed in the state where the polymer and the hydrophilic particles are dissolved together in the solvent, It is possible to prepare a spinning solution having evenly dispersed color-changing dye particles.

The method (b) and the method (d) of the method 1 are a step of spinning the composite spinning nanofiber with the hydrophilic particles and the color-changing dye material bound to the electro spinning solution by an electrospinning process, To thereby maximize the amount of the color-changing dye material that is bound to the nanofibers uniformly and exposed to the air. In addition, the hydrophilic particles bind to the inside and the outside of the nanofiber and induce moisture in the air to be adsorbed in the membrane. It is important that nanofiber polymers structure and physically encapsulate the color change dye material because the color change dye powder can easily be desorbed from the nanofiber when the binding strength between the color change dye material and the nanofiber is weak. When the electrospinning method is used, the color-changing dye material is mixed with the electrospinning solution and is radiated so that the color-changing dye material binds to the matrix of the polymer nanofiber.

Method 1 (c) and Method 2 (e) are conducted by spinning one-dimensional nanofibers emitted by electrospinning to a certain thickness or more (preferably 5 탆 or more) to bind hydrophilic particles and color- Thereby forming a composite polymer nanofiber membrane. When the thickness of the membrane formed on the current collector is small, it is difficult to expect dark color change characteristics because the number of collected fiber strands is small. The composite polymer nanofiber membrane may be electrospun on the top of the support which is easy to handle. Examples of the easy-to-handle support include stainless steel, paper, non-woven fabric, and plastic substrate. A composite polymer nanofiber having a hydrophilic particle and a color-changing dye material attached to the upper surface of various supports Membrane can be formed. The thickness of the composite nanofiber membrane formed on the support may be in the range of 5 to 1000 mu m. It is easier to manufacture a composite polymer nanofiber membrane sensor in which hydrophilic particles and color change dye materials are bound by direct irradiation onto a support that is easy to process. When a specific gas molecule is adsorbed and reacts with the color-changing dye material, the change in the frequency of the wavelength in the visible light region, the change in the frequency of the outward wavelength in the visible light region, the change in the frequency of the wavelength in the outside of the visible light region, The color change occurs due to the change.

According to the present invention, by forming a one-dimensional nanofiber membrane including hydrophilic particles and a color change dye material at the same time, the hydrophilic particles absorb moisture in the air to increase the reactivity between the specific gas molecules and the color change dye material, The present invention can produce a gas-indicating composite polymer nanofiber membrane color change sensor which exhibits excellent color change performance even with a color change dye material and has a three-dimensional network structure of the nanofibers.

The gas-indicating composite polymer nanofiber membrane color-change sensor, in which a hydrophilic particle and a color-changing dye material are bonded to a one-dimensional nanofiber structure produced by an electrospinning process, has a higher surface area And porosity. Therefore, even when exposed to a gas having a concentration lower than 1 ppm, it is possible to cause a color change within a few tens of seconds to generate a biochemical indicator gas (CH ₃ COCH ₂ ) contained in environmentally harmful gases (H ₂ S, SO _x , NO _x , CO _x ) ₃ , C ₂ H ₅ OH, C ₆ H ₅ CH ₃ ) can be used as a color change gas sensor capable of detecting high sensitivity / high speed.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
FIG. 1 is a schematic view of a gas indicator complex polymer nanofiber membrane color sensor in which hydrophilic particles and color change dye materials are bound to a one-dimensional nanofiber structure according to an embodiment of the present invention.
FIG. 2 is a view showing a manufacturing process of a gas indicator complex polymer nanofiber membrane color change sensor in which hydrophilic particles and color change dye materials are bonded to a one-dimensional nanofiber structure using an electrospinning process according to an embodiment of the present invention to be.
FIG. 3 is a graph showing the results of measurement of the refractive indices of a gas-indicating composite polymer nanofiber membrane (hereinafter, referred to as " polymer nanofiber ") having a hydrophilic particle and a color-changing dye material bonded to a 1-dimensional nanofiber structure using an electrospinning process according to Example 1 of the present invention, A method 1 for producing a color change sensor, and a gas indicator complex polymer nanofiber membrane color change sensor in which hydrophilic particles and a color change dye material are bonded to a one-dimensional nanofiber structure to which a high temperature stirring and quenching process according to Example 2 is applied 2 is a flow chart of the manufacturing method.
4 is a scanning electron micrograph of alumina (Al ₂ O ₃ ) powder which is an example of the hydrophilic particles used in Example 1 and Example 2 of the present invention.
FIG. 5 is a scanning electron microscope (SEM) image of a color change dye material (lead (II) acetate) for hydrogen sulfide gas indicated by the high energy ball milling process according to Example 1 of the present invention.
FIG. 6 is a graph showing the results of measurement of hydrophobic particles (Al ₂ O) of 60 wt%, (b) 30 wt% and (c) 15 wt% based on the weight of the polymer, ₃ ) and 300 wt% color change dye material (Lead (II) acetate).
FIG. 7 is a graph showing the relationship between the amount of dye-transition dye (Lead (II) acetate) of 300 wt% based on the weight of the polymer, It is a microscopic photograph.
(A) 60 wt%, (b) 30 wt%, (c) 15 wt%, and (b) 30 wt%, based on the weight of the polymer, of the 1-dimensional nanofiber structure prepared according to Example 2 % Of hydrophilic particles (Al ₂ O ₃ ) and 300 wt% color-changing dye material (Lead (II) acetate).
FIG. 9 is a graph showing the relationship between the amount of a color change dye material (lead (II) acetate) bound to a polymer and the amount of a color change dye material (Lead (II) acetate) bound to a 1-dimensional nanofiber structure produced according to Comparative Example 2 of the present invention SEM photographs of the composite polymer nanofibers for use in the present invention.
FIG. 10 is a graph showing the relationship between the amount of hydrophilic particles (Al ₂ O ₃ ) and the color change dye material (Lead (II) acetate) bound to 15, 30 and 60 wt% of the polymer prepared in Example 1, Indicated composite polymer nanofiber membranes and polymer prepared according to Comparative Example 1 were mixed with 300 wt% of the color change dye material (lead (II) acetate) alone. Of the polymer nanofiber membrane sensor obtained by direct exposure of 1 ppm to 30 seconds, 1 ppm to 1 minute, and 5 ppm to 1 minute, respectively.
Fig. 11 quantitatively shows the degree of color change (RGB variation) before and after exposure to the hydrogen sulfide gas of each sample in order to quantitatively analyze the color change more precisely based on the scan image of Fig.
Figure 12 is the first embodiment of the polymer hydrophilic particles of 60 wt%, based on the weight of the produced according to (Al ₂ O ₃₎ and the color change dye material (Lead (II) acetate) of 300 wt% the binder gas composite polymer-indicating nano The scan image shows the degree of color change when the exposure time at the hydrogen sulfide gas concentration 5 ppm of the fiber membrane is increased to 0, 10, 20, 30, 40, 50, and 60 seconds.
13 is a second embodiment (high-temperature stirring and quenching processes including) the polymer based on the weight of each of 15, 30, the hydrophilic particles of _{60 wt% (Al 2 O 3} ) and the color change of 300 wt% dye material prepared according to (Lead ( II) acetate-bound polymeric nanofibers and 300 wt% color-changing dye material (Lead (II) acetate) only in the polymer prepared according to Comparative Example 2 (including high temperature stirring and quenching process) The color change degree of the composite polymer nanofiber membrane sensor obtained by directly exposing the hydrogen sulfide gas to 1 ppm for 30 seconds, 1 ppm for 1 minute, and 5 ppm for 1 minute to the gas indicator complex polymer nanofiber color change sensor Respectively.
FIG. 14 quantitatively shows the degree of color change (RGB variation amount) before and after exposure to the hydrogen sulfide gas of each sample for quantitative analysis of the color change based on the scan image of FIG. 13.
FIG. 15 is a graph showing the relationship between the weight ratio of 60 wt% hydrophilic particles (Al ₂ O ₃ ) and 300 wt% color change dye material (lead (II) acetate) to polymer prepared according to Example 2 (including high temperature stirring and quenching process) The scan image shows the degree of color change when the exposure time at the hydrogen sulfide gas concentration 5 ppm of the gas-indicating composite polymer nanofiber membrane was increased to 0, 10, 20, 30, 40, 50, and 60 seconds.
FIG. 16 is a graph showing the results of measurement of the refractive indices of the gas-indicating composite polymer (A) obtained by binding 60 wt% of hydrophilic particles (Al ₂ O ₃ ) and 300 wt% of color-changing dye material (RGB variation) before and after exposure to hydrogen sulfide gas when exposed to hydrogen sulfide for 1 minute at 1 ppm between a nanofiber membrane and a commercially available commercial hydrogen sulfide sensing material (Johnson company).

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are described in detail below with reference to the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, a gas-indicating composite polymer nanofiber membrane color sensor in which a hydrophilic particle and a color-changing dye material are bonded to a one-dimensional nanofiber structure will be described in detail with reference to the accompanying drawings.

The present invention relates to a method for manufacturing a gas indicator complex polymer nanofiber membrane color change sensor in which hydrophilic particles and color change dye materials are uniformly bound to one-dimensional nanofibers using an electrospinning method, , It is possible to adsorb moisture in the air by bonding the hydrophilic particles to the environment to increase the reactivity between the specific gas molecules and the color change dye material. Thus, even when a small amount of color change dye material is used, .

In the case of a conventional color change gas sensor, a method of attaching a color change dye material to a polymer is mainly used in order to prevent the color change dye material from being desorbed out of the product during use. However, the conventional synthesis method has a disadvantage that the reactivity between the gas molecule and the color change dye material is low and the reaction time is long. Also, excessive color change dye materials should be used to increase the color change performance and gas molecules must be exposed to the color change dye material for a long time. Particularly, since the color change of the color change dye material is irreversible, the color change sensor can not be used as a disposable product, and most of the color change dye materials contain a heavy metal element. Therefore, in order to commercialize the color change sensor, it is necessary to make an ideal environment in which a color change dye can perform a surface chemical reaction at a high speed with a gas effect and a vivid color change, even though a very small amount of color change dye material is used. It is necessary to develop a color change gas sensor having high sensitivity and fast reaction speed.

In order to solve such problems, the present invention provides a method for manufacturing a gas-indicating composite polymer nanofiber membrane color-change sensor in which a color-changing dye material having adsorbed and reacted with hydrophilic particles and specific gas molecules is changed to change color. When the color change dye material is bound to the polymer nanofibers having a three-dimensional open pore structure, the surface area exposed to the target gas can be greatly increased. In addition, since the diffusion of gas is easy, a much darker color change characteristic than the color change dye coated on the two-dimensional film can be expected. However, despite the advantage of having a large specific surface area due to insufficient reactivity between a specific gas molecule and a color change dye material, it is still difficult to detect a low concentration gas molecule. The present invention relates to a method and apparatus for uniformly binding hydrophilic particles and color change dye materials to nanofibers using an electrospinning process and inducing hydrophilic particles to adsorb moisture in the air to increase the reactivity between the gas molecules and the color change dye material, The present invention provides a nanofiber membrane color change sensor and a method of fabricating the same, wherein the color change dye exhibits high sensitivity even when the color change dye binds.

FIG. 1 is a schematic diagram of a composite polymer nanofiber membrane sensor 101 according to an embodiment of the present invention.

The polymer nanofiber membrane sensor 101 includes a polymer nanofiber 102 having a three-dimensional network structure. The polymer nanofiber 102 has a color change dye material 103, which is adsorbed and reacted with a specific gas molecule, And hydrophilic particles 104 for inducing adsorption of moisture in the air. At this time, the composite polymer nanofiber membrane sensor 101 forms a three-dimensional porous membrane structure in which polymer nanofibers 102 having a one-dimensional structure are randomly entangled with each other or stacked in a predetermined direction .

The hydrophilic particles 104 having a diameter ranging from 2 nm to 500 nm, which can induce the membrane to become hydrophilic and absorb moisture in the air, are uniformly adhered to the polymer nanofiber 102 without aggregation, hydrophilic particles 104 to the oxide particle having a polar _{nature, antimony tetroxide (Sb 2 O 4} ), cobalt (II, III) oxide (Co 3 O 4), iron (II, III) oxide (Fe 3 O 4) , lead (II, IV) oxide (Pb 3 O 4), manganese (II, III) oxide (Mn 3 O 4), silver (I, III) oxide (Ag 2 O 2), triuranium octoxide (U 3 O 8 ), copper (I) oxide ( Cu 2 O), dicarbon monoxide (C 2 O), dichlorine monoxide (Cl 2 O), lithium oxide (Li 2 O), potassium oxide (K 2 O), rubidium oxide (Rb 2 O), silver oxide ([Ag 2 O), thallium (I) oxide (Tl 2 O), sodium oxide (Na 2 O), aluminium (II) oxide (AlO), barium oxide (BaO), beryllium oxide (BeO ), cadmium oxide (CdO), calcium oxide (CaO), chromium (II) oxide (CrO), cobalt (II) oxide (CoO) (II) oxide (NiO), palladium (II) oxide (PdO), strontium oxide (PbO), and lead (II) oxide (PbO) SrO), sulfur monoxide (SO) , disulfur dioxide (S 2 O 2), tin (II) oxide (SnO), titanium (II) oxide (TiO), vanadium (II) oxide (VO), zinc oxide (ZnO) _{, aluminium oxide (Al 2 O 3} ), antimony trioxide (Sb 2 O 3), arsenic trioxide (As 2 O 3), bismuth (III) oxide (Bi 2 O 3), boron trioxide (B 2 O 3), chromium _{(III) oxide (Cr 2 O} 3), dinitrogen trioxide (N 2 O 3), erbium (III) oxide (Er 2 O 3), gadolinium (III) oxide (Gd 2 O 3), gallium (III) oxide ( _{Ga 2 O 3), holmium (} III) oxide (Ho 2 O 3), indium (III) oxide (In 2 O 3), iron (III) oxide (Fe 2 O 3), lanthanum oxide (La 2 O 3) , lutetium (III) oxide (Lu 2 O 3), nickel (III) oxide (Ni 2 O 3), phosphorus trioxide (P 4 O 6), promethium (III) oxide (Pm 2 O 3), rhodium (III) _{oxide (Rh 2 O 3),} samarium (III) oxide (Sm 2 O 3), scandium oxide (Sc 2 O 3), terbium (III) oxide (Tb 2 O 3), thallium (III) ox _{ide (Tl 2 O 3),} thulium (III) oxide (Tm 2 O 3), titanium (III) oxide (Ti 2 O 3), tungsten (III) oxide (W 2 O 3), vanadium (III) oxide ( _{V 2 O 3), ytterbium (} III) oxide (Yb 2 O 3), yttrium (III) oxide (Y 2 O 3), cerium (IV) oxide (CeO 2), chlorine dioxide (ClO 2), chromium (IV _{) oxide (CrO 2), dinitrogen} tetroxide (N 2 O 4), germanium dioxide (GeO 2), hafnium (IV) oxide (HfO 2), lead dioxide (PbO 2), manganese dioxide (MnO 2), plutonium (IV _{) oxide (PuO 2), rhodium} (IV) oxide (RhO 2), ruthenium (IV) oxide (RuO 2), selenium dioxide (SeO 2), silicon dioxide (SiO 2), sulfur dioxide (SO 2), tellurium dioxide _{(TeO 2), thorium dioxide (} ThO 2), tin dioxide (SnO 2), titanium dioxide (TiO 2), tungsten (IV) oxide (WO 2), uranium dioxide (UO 2), vanadium (IV) oxide (VO _{2), zirconium dioxide (ZrO 2} ), antimony pentoxide (Sb 2 O 5), arsenic pentoxide (As 2 O 5), dinitrogen pentoxide (N 2 O 5), niobium pentoxide (Nb 2 O 5), phosphorus pentoxide (P ₂ O ₅ ), tantalum pentoxide (Ta ₂ O ₅ ), _{vanadium (V) oxide (V 2} O 5), chromium trioxide (CrO 3), molybdenum trioxide (MoO 3), rhenium trioxide (ReO 3), selenium trioxide (SeO 3), sulfur trioxide (SO 3), tellurium trioxide ( _{TeO 3), tungsten trioxide (WO} 3), uranium trioxide (UO 3), xenon trioxide (XeO 3), manganese heptoxide (Mn 2 O 7), rhenium (VII) oxide (Re 2 O 7), technetium (VII) _{oxide (Tc 2 O 7),} osmium tetroxide (OsO 4), ruthenium tetroxide (RuO 4), xenon tetroxide (XeO 4), iridium tetroxide (IrO 4), hassium tetroxide 1 jong oxide or two or more of (HsO ₄₎ Oxides may be mixed and used.

The polymer nanofiber 102 is subjected to adsorption and reaction with a specific gas to change the frequency of the wavelength within the visible light region, the frequency of the wavelength outside the visible light region, the frequency of the wavelength inside the visible light region, The color change dye material 103 including an average diameter ranging from 1 nm to 1 탆 exhibiting color change characteristics due to a change in intensity of a wavelength is bound without being agglomerated and the color change dye material 103 is lead (II) acetate (Pb (CH 3 COO) 2), iron (II) acetate (Fe (CH 3 COO) 2), nickel (II) acetate (Ni (CH 3 COO) 2), copper (II) acetate ( _{Cu (CH 3 COO) 2)} , cadmium acetate (Cd (CH 3 COO) 2), cobalt (II) acetate (Co (CH 3 COO) 2), manganese (II) acetate (Cu (CH 3 COO) 2) , bismuth (III) acetate (Co (CH 3 COO) 3), silver (I) acetate (Ag (CH 3 COO)), silver nitride (AgNO 3), o-tolidine, m-tolidine, bromophenol blue + TBAH, methyl red + TBAH, thymol blue + TBAH, fluoresc (II), 5-10-15-20-tetrakis (2,4,6-trimethylphenyl) porphyrinatozinc (II), or a mixture of _two or more compounds selected from the group consisting of bromocresol purine, bromocresol purine, bromophenol red, LiNO3, 5-10-15-20-tetraphenylporphyrinatozinc Mixtures of two or more may be used.

The polymer solution containing the hydrophilic particles 104 and the color change dye material 103 is electrospun to prevent the hydrophilic particles 104 and the color change dye material 103 from being desorbed from the polymer nanofibers 102, Characterized in that the nanofibers (102) structurally and physically envelop the hydrophilic particles (104) and the color change dye material (103).

The diameter of the polymer nanofiber 102 produced through the electrospinning process is in the range of 100 nm to 10 μm. The acetate-based color-changing dye materials 103 listed above are dyes which are capable of achieving a specific color change particularly in the reaction with hydrogen sulfide. However, in addition to the dyes listed above, the dyes capable of exhibiting color change characteristics through selective reaction bonding with a specific gas do not limit the binding of the hydrophilic particles 104 with the nanofibers 102 containing the hydrophilic particles 104.

2 is a schematic diagram of an electrospinning apparatus used in Embodiment 1 of the present invention.

An electrorheological fluid containing hydrophilic particles and a color change dye material is discharged from a needle of a syringe 201 through an electrospinning process and is discharged as a one-dimensional composite polymer nanofiber membrane. A strong electric field is applied to the needle of the syringe 201 by the high voltage applying device 202, and the discharged electrospinning solution is radiated to the current collector 203. During the electrospinning process, the solvent evaporates and one-dimensional nanofibers are obtained.

The solvent used in the preparation of the polymer solution is selected from the group consisting of water (deionized water), tetrahydrofuran, methanol, isopropanol, formic acid, acetonitrile, It is also possible to use nitromethane, acetic acid, ethanol, acetone, ethylene glycol (EG), dimethyl sulfoxide (DMSO), dimethylformamide (DMF) Dimethylacetamide (DMAc), and toluene may be used as the solvent.

The nanofibers emitted through the electrospinning process have a one-dimensional structure, and are attached to the color change dye material 205 and the polymer 204, which bind to the polymer 204 and react with specific gas molecules to cause color change And hydrophilic particles 206 that adsorb moisture in the air to enhance the reactivity between the specific gas molecules and the color change dye material 205.

In addition, since the nanofibers radiated through the electrospinning process can be coated with the color-changing dye material 205 in a shape surrounding the hydrophilic particles 206, excellent color change characteristics There is an advantage that it can be expected.

The polymer 204 may be at least one selected from the group consisting of polypropyl alcohol (PPFA), polymethyl methacrylate (PMMA), polyacrylic copolymer, polyvinyl acetate (PVAc), polyvinyl acetate copolymer, polystyrene polystyrene, polystyrene, polyvinylpyrrolidone (PVP), polystyrene copolymer, polyethylene oxide (PEO), polyethylene oxide copolymer, polycarbonate (PC), polyvinyl chloride Oxide copolymer, polycaprolactone, polyvinyl fluoride, polyvinylidene fluoride (PVDF), polyvinylidene fluoride copolymer, polyimide, polyacrylonitrile (PAN, polyacrylonitrile), polyethylene terephthalate (PET), polypropylene oxide (PPO), polyvinyl alcohol (PVA), poly vinyl alcohol, SAN, styrene-acrylonitrile, polycarbonate, polyaniline, polypropylene, and polyethylene (PE). Or a mixture of two or more kinds of polymers.

In order to obtain an appropriate viscosity for conducting electrospinning, the polymer constituting the electrospinning solution is prepared in a specific solvent in a concentration range of 0.1 to 90 wt% by weight. The average particle sizes of the hydrophilic particles and the color-changing dye materials are in the range of 2 nm to 500 nm and 1 nm to 1 μm, respectively, and the weight ratio of the hydrophilic particles to the color-changing dye material is Is contained in a concentration range of 0.1 to 100 wt% and 0.1 to 400 wt%, respectively.

The color changing dye materials may be selected from the group consisting of ball milling, gyratory crusher, hammer mill, jaw crusher, corn mill, roll crusher, Such as an edge runner, a ring-roll mill, a stamp mill, a rod mill, a screw shear mill, an impact mill, a jet mill, A pulverizer, a pulverizer, a colloid mill, a sonication, or the like.

The hydrophilic particles and the color change dye material may be dispersed in a polymer solution dissolved in a solvent or may be used by using a polymer solution recrystallized from a color change dye material as microcrystals through a high temperature stirring and quenching process do.

Additionally, detailed description of Method 2 involving high temperature agitation and quenching involves mixing the electrospray solution containing the color changing dye material, hydrophilic particles, polymer and solvent at a temperature above the melting point of the color changing dye material Dissolving the color-changing dye material in a solvent, and quenching the mixed electric spinning solution again at a temperature of 25 ° C or lower.

In the electrospinning process, the discharge amount for discharging the electrical discharge solution has a range of 0.1 μl / min to 500 μl / min, respectively, and can be appropriately selected according to the viscosity of the spinning solution. By controlling the ratio of the concentration of the spinning solution and the injection rate, it is possible to manufacture the nanofiber by adjusting the diameter of the finally produced nanofiber.

A voltage of 1 to 50 kV may be applied between the nozzle and the collecting plate (collector), and the distance between the nozzle and the collector may be selected in the range of 3 to 50 cm. The collector plate is characterized by using a support which is easy to handle such as stainless steel, paper, nonwoven fabric, plastic substrate and the like. And the thickness of the nanofiber membrane is in the range of 5 탆 to 1000 탆. When the thickness of the fiber is smaller than 5 탆, the density of the collected nanofibers is not sufficiently high and dark color change characteristics can not be expected. When the thickness is more than 1000 탆, , And it is preferable to prepare a membrane having a thickness range of from 10 mu m to 30 mu m in order to obtain deep color change characteristics while minimizing the loading amount of the dye.

In the composite polymer nanofiber membrane color change sensor in which hydrophilic particles and color change dye materials are bonded, specific gas molecules are adsorbed to and reacted with the color change dye material on the individual fiber surface when exposed to a specific gas, The hydrophilic particles absorb moisture in the air to increase the reactivity between the specific gas molecules and the color-changing dye material, thereby enhancing the color change sensitivity. These membrane color change sensors are environmentally harmful gases (H ₂ S, SO _x , NO _x , CO _x ) and biological indicator gases (CH ₃ COCH ₃ , C ₂ H ₅ OH, and C ₆ H ₅ CH ₃ ) contained in human exhalation.

FIG. 3 is a flowchart illustrating a method of fabricating a nanofiber membrane color change sensor in which hydrophilic particles and color change dye materials are bound using an electrospinning process according to an embodiment of the present invention.

As shown in the flowchart of FIG. 3, there are two methods for producing the color-changing membrane sensor. In method 1, hydrophilic particles and color-changing dye materials are added to a polymer solution in which a polymer is dissolved in a solvent, Step 301: irradiating the one-dimensional polymer composite nanofibers having the hydrophilic particles and the color-changing dye material bound using the electrospinning process (Step 304), collecting the polymer nanofibers in the form of a membrane in a nonwoven fabric Step 305. FIG.

The method 2 comprises the steps of (301) preparing an electric spinning solution by adding a hydrophilic particle and a color-changing dye material to a polymer solution in which a polymer is dissolved in a solvent, (301) A step (302) of dissolving the color-changing dye material, a step (303) of preparing an electrospinning solution containing a color-changing dye material solidified into microcrystals through quenching, a step (303) A step 304 of radiating the one-dimensional polymer composite nanofibers to which the dye material is bound, and a step 305 of collecting the polymer composite nanofibers in the form of a membrane in the nonwoven fabric.

Further, a hydrophilic particle and the color change dye material produced binder polymer composite nanofiber membrane changes color sensor hazardous gases (H ₂ S, SO _x, NO _x, CO _x), and biomarkers gas contained in the exhalation of a person _{(CH 3 COCH 3, C 2} H 5 OH, C 6 H 5 CH 3) is applied to the sensor changes color it is possible to detect.

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples. The examples and comparative examples are merely intended to illustrate the present invention, and the present invention is not limited to the following examples.

Example  1: a product obtained through a grinding process Color change  An electrospinning process comprising dye particles is used to separate the gas-indicating hydrophilic particles Color change  The dye material Concluded  Composite polymer nanofiber Membrane Color change  Manufacture of sensor

First, in order to impart hydrophilicity to nanofibers in order to absorb moisture in the air and increase the reactivity between the specific gas and the color-changing dye, an aqueous solution of 50 nm or less of Al ₂ O ₃ (Aluminum oxide) particles are prepared.

FIG. 4 is a graph showing the relationship between the prepared Al ₂ O ₃ Scanning electron micrographs of the particles show partial aggregation of Al ₂ O ₃ particles of 50 nm or less. The Al ₂ O ₃ particles uniformly dispersed in the mixed electric spinning solution can be obtained through sufficient agitation.

In order to use lead (II) acetate, which exhibits color change by reaction with hydrogen sulfide, in a particle form, lead (II) acetate having a size of 100 μm or more is subjected to a high energy ball milling process (Lead (II) acetate) in the form of particles smaller than ㎛ in size.

FIG. 5 is a scanning electron micrograph of lead (II) acetate pulverized through a high energy ball milling process. The size (any one of diameter, length and thickness depending on the shape of the nano powder) is 1 nm to 1 It can be confirmed that a dye powder having a size range of < RTI ID = 0.0 > g / m < / RTI > Partially agglomerated lead acetate particles are observed, but lead acetate particles of the corresponding size range can be bound to the electrospun fiber by sufficient agitation of the electrospinning solution.

0.15 g of polyacrylonitrile (PAN) having a molecular weight of 130,000 g / mol was dissolved in 2 ml of dimethylformamide (DMF) according to the preparation method of Method 1 in order to prepare an electrospinning solution to be injected into a syringe. ). In addition, each of 15 wt%, 30 wt%, and 60 wt% of Al ₂ O ₃ (Aluminum (II) acetate) was added to the polymer / solvent composite solution at a rotation speed of 500 rpm for 12 hours at room temperature, Use solution is prepared. After dissolving the polymer (PAN), hydrophilic particles (Al ₂ O ₃ ) and color change dye (lead (II) acetate) in a solvent (DMF) with sufficient agitation, electrospinning is carried out using mixed electric spinning solution. First, the prepared spinning solution is put in a syringe (12 ml NORM-JECT) and connected to a syringe pump. The electrospinning solution is pushed out at a discharge rate of 1 ml / min and a nozzle needle, 23 gauge) and the collector collecting nanofibers at 12 kV. At this time, a stainless steel plate is used as a collector plate, and a distance between the nozzle and the collector is maintained at 15 cm.

FIG. 6 is a graph showing the results of measurement of hydrophobic particles (Al ₂ O) of 60 wt%, (b) 30 wt% and (c) 15 wt% based on the weight of the polymer, ₃ ) and 300 wt% color change dye material (lead (II) acetate).

SEM photographs of hydrophilic particles prepared by electrospinning and color-changing dye material-bound complex polymer nanofibers are shown in FIG. 1, which shows that hydrophilic particles having a size range of 300 nm or less are formed on polymer nanofibers having a diameter of about 500 nm And a color change dye material having a size range of 1 μm or less are well adhered to each other. Particularly, it can be confirmed that the hydrophilic particles (Al ₂ O ₃ ) are uniformly and well bonded to the inside and the surface of the composite polymer nanofibers, and thus the spherical and rugged structural characteristics are exhibited. For picture (a) of FIG hydrophilic particles (Al ₂ O ₃₎ a large amount of the hydrophilic particles (Al ₂ O ₃₎ as a 60 wt% level, based on the weight of the polymer content of the bumpy as a binder for nano-fiber interior and the surface A nanofiber membrane is formed in the form of a nanofiber structure and at the same time, the color-changing dye material is uniformly bonded to the nanofiber structure. On the other hand, as shown in photographs (b) and (c) of FIG. 6, when the content of the hydrophilic particles (Al ₂ O ₃ ) is as low as 30 wt% or 15 wt% with respect to the weight of the polymer, The amount of the particles (Al ₂ O ₃ ) is not sufficient and the reaction with the external gas is expected to be limited as compared with the case of the photograph (a). In particular, as the degree of surface exposure of the hydrophilic particles increases, a desirable environment for increasing the reactivity between the color-changing dye material and the gas can be created. The initial powder size of the hydrophilic particles (Al ₂ O ₃ ) is 50 nm, but it can be seen that it has a size range of 50 nm to 300 nm in the agglomeration process. In order to disperse more uniform hydrophilic particles, Al ₂ O ₃ powder that has been pulverized by micro bead-milling may be used.

Comparative Example  1. Using the electrospinning method described above, only the color-changing dye material except the hydrophilic particles is uniformly dispersed in the polymer nanofibers Concluded  With gas indicator Color change  Dye material composite polymer nanofiber Membrane Color change  sensor

In Comparative Example 1, which was compared with Example 1, electrospinning liquid containing the same amount of color-changing dye material as that of Example 1 was electrospun without adding hydrophilic particles to prepare color change dye powder (lead (II) acetate ) Can be used to produce a gas-indicating color-changing dyestuff composite polymer nanofiber membrane color-change sensor bonded to a polymer nanofiber. Specifically, 0.15 g of polyacrylonitrile (PAN) having a molecular weight of 130,000 g / mol is first dissolved in 2 ml of dimethylformamide (DMF). Thereafter, lead (II) acetate (300 wt%) was added to the polymer / solvent complex solution, and the solution was stirred at 500 rpm for 12 hours at room temperature. . After dissolving the polymer (PAN) and color change dye (lead (II) acetate) in a solvent (DMF) with sufficient agitation, electrospinning is performed using a mixed electric spinning solution. First, the prepared spinning solution is put in a syringe (12 ml NORM-JECT) and connected to a syringe pump. The electrospinning solution is pushed out at a discharge rate of 1 ml / min and a nozzle needle, 23 gauge) and the collector collecting nanofibers at 12 kV. At this time, a stainless steel plate is used as a collector plate, and a distance between the nozzle and the collector is maintained at 15 cm. Since the color-changing dye / polymer composite nanofiber synthesized through Comparative Example 1 does not contain hydrophilic particles, it can not sufficiently adsorb moisture in the air due to its hydrophobicity. Therefore, the surface reaction between the specific gas molecule and the color- It can not provide an ideal environment to promote.

FIG. 7 is a graph showing the relationship between the amount of the coloring dye material (lead (II) acetate) of 300 wt% based on the weight of the polymer, It is a microscopic photograph.

Unlike the scanning electron microscope photograph of Example 1, because it is a color change dye / polymer composite nanofiber that does not contain hydrophilic particles, the surface of the nanofiber is relatively smooth without showing the shape of the rugged hydrophilic particle on the surface do. It can be seen that a color change dye material having a diameter of about 500 nm and having a size similar to that of Example 1 is bound, and a considerable number of color change dye particles are wrapped inside the nanofiber by a polymer Can be confirmed. In such a case, the exposure of the color-changing dye material capable of reacting with a specific gas in the air is limited, thereby lowering the sensitivity of the color change.

Example  2: In the production process of the electric discharge fluid High temperature agitation and  The quenching process is added and the hydrophilic particles and Color change  Dye materials evenly Concluded  With gas indicator Color change  Dyestuff composite nanofiber Membrane Color change  Manufacture of sensor

First, in the same manner as in Example 1, hydrophilic Al ₂ O _{3 (} not more than 50 nm) capable of absorbing moisture in the air and increasing reactivity with a specific gas and color change dye (lead (Aluminum oxide) particles are prepared.

0.15 g of polyacrylonitrile (PAN) having a molecular weight of 130,000 g / mol was dissolved in 2 ml of dimethylformamide (DMF) according to the preparation method of Method 2 to prepare an electrospinning solution to be injected into the syringe. ). In addition, each of 15 wt%, 30 wt%, and 60 wt% of Al ₂ O ₃ (Aluminum oxide) and 300 wt% of lead (II) acetate (lead (II) acetate) relative to the weight ratio of the polymer not subjected to ball milling to the polymer / And stirring is performed at a rotational speed of 500 rpm for 12 hours at 85 ° C or higher to prepare a spinning liquid by liquefying lead acetate trihydrate. After dissolving the polymer (PAN), hydrophilic particles (Al ₂ O ₃ ) and color change dye (lead (II) acetate) in a solvent (DMF) with sufficient agitation, the heated electrospinning solution is heated to 25 ° C To induce recrystallization of fine lead acetate particles in the electrospinning solution. In this case, the quenching process is performed by rapidly immersing a vial containing electrospinning solution containing polymer (PAN), hydrophilic particles (Al ₂ O ₃ ) and color change dye (lead (II) acetate) It is possible to induce recrystallization of the color-changing dye. In other words, when lead acetate (lead (II) acetate) is selected as the dye material, the mixed solvent is stirred at a temperature of 75 ° C or higher, known as the melting point of lead acetate, to liquefy the lead acetate trihydrate, May be quenched at a temperature of 25 ° C or less to form fine lead acetate crystals within the electrodeposition solution. Thereafter, electrospinning is performed using a mixed electric spinning solution. First, the prepared spinning solution is put in a syringe (Henke-Sass Wolf, 12 ml NORM-JECT) and connected to a syringe pump, and the electrospinning solution is pushed at a discharge rate of 1 ml / min. The voltage between the needle (23 gauge) used in the spinning process and the current collecting nano fiber is set to 12 kV to conduct electrospinning. At this time, a stainless steel plate is used as a collector plate, and a distance between the nozzle and the collector is maintained at 15 cm.

(A) 60 wt%, (b) 30 wt%, (c) 15 wt%, and (b) 30 wt%, based on the weight of the polymer, of the 1-dimensional nanofiber structure prepared according to Example 2 % Of hydrophilic particles (Al ₂ O ₃ ) and 300 wt% color-changing dye material (Lead (II) acetate).

SEM photographs of hydrophilic particles prepared by electrospinning and color-changing dye material-bound complex polymer nanofibers are shown in FIG. 1, which shows that hydrophilic particles having a size range of 300 nm or less are formed on polymer nanofibers having a diameter of about 500 nm And a color change dye material having a size range of 1 μm or less are well adhered to each other. Particularly, hydrophilic particles (Al ₂ O ₃ ) are uniformly and well bonded to the inside and the surface of the composite polymer nanofiber, so that it is confirmed that the nanofiber has a spherical, rugged, have. As the content of the hydrophilic particles (Al ₂ O ₃ ) increases, the surface roughness of the nanofibers increases. In the case of the photograph (a) of FIG. 8, when the amount of the hydrophilic particles (Al ₂ O ₃ ) is 60 wt% or more relative to the weight of the polymer, the nanofibers have a very uneven structure It can be seen that a very ideal form of nanofiber membrane, in which the color change dye material is well bonded, is synthesized. On the other hand, as shown in the photographs (b) and (c) of FIG. 8, when the content of the hydrophilic particles (Al ₂ O ₃ ) is as low as 30 wt% or 15 wt% with respect to the weight of the polymer, The amount of the particles (Al ₂ O ₃ ) is not sufficient and the reaction with the external gas is expected to be limited as compared with the case of the photograph (a). As described above, as the degree of surface exposure of the hydrophilic particles (Al ₂ O ₃ ) increases, an environment favorable for the reaction between the color-changing dye and the gas can be created.

Comparative Example  2. In the production process of the electric discharge fluid High temperature agitation and  The quenching process was added, and by using electrospinning, Color change  Only the dye material can be evenly applied to the polymer nanofiber Concluded  With gas indicator Color change  Dye material composite polymer nanofiber Membrane Color change  sensor

In Comparative Example 2 as compared with Example 2, an electrospinning liquid containing the same amount of color-changing dye material as in Example 2 was not electroposited, but only the color-changing dye powder was adhered to the polymer nanofibers Fabrication of colorimetric dye-composite polymer nanofiber membrane sensor for gas indication. Specifically, 0.15 g of polyacrylonitrile (PAN) having a molecular weight of 130,000 g / mol is first dissolved in 2 ml of dimethylformamide (DMF). After that, the lead (II) acetate solution was dissolved in a polymer / solvent complex solution containing 300 wt% of lead (II) acetate, which was not subjected to the ball milling process. ° C) at 85 ° C or higher for 12 hours at a rotation speed of 500 rpm to prepare a spinning solution. After dissolving the polymer (PAN) and color change dye (lead (II) acetate) in a solvent (DMF) through sufficient agitation, the heated electrospinning solution is quenched to a temperature of 25 ° C or lower, Lead to recrystallization of lead acetate particles. First, the prepared spinning solution is put in a syringe (12 ml NORM-JECT) and connected to a syringe pump. The electrospinning solution is pushed out at a discharge rate of 1 ml / min and a nozzle needle, 23 gauge) and the collector collecting nanofibers at 12 kV. At this time, a stainless steel plate is used as a collector plate, and a distance between the nozzle and the collector is maintained at 15 cm. The color change dye / polymer composite nanofiber lacking the hydrophilic particle synthesized through Comparative Example 2 is relatively hydrophobic as compared with Example 2, so that it can not absorb a sufficient amount of moisture, There are limitations in providing an environment that promotes surface chemical reactions.

Fig. 9 is a graph showing the results of a scanning electron microscope (SEM) of a gas-indicating composite polymer nanofiber in which only 300 wt% of a color change dye material (lead (II) acetate) is bound to a 1-dimensional nanofiber structure produced according to Comparative Example 2 of the present invention. It is a microscopic photograph.

There is no appearance of the hydrophilic particles (Al ₂ O ₃₎ cases, the color change dye / polymer composite nanofibers do not contain the second embodiment of the scanning electron microscope, unlike the hydrophilic particles (Al ₂ O ₃₎ rough surface , And only a color change dye material in an elongated particle form is bound to form a relatively smooth nanofiber surface. The produced polymer composite nanofiber has a diameter of about 500 nm and is characterized in that the color-changing dye material bound inside is surrounded by the polymer. As described above, in the case of a nanofiber membrane in which hydrophilic particles (Al ₂ O ₃ ) are not contained and only the color-changing dye material is enclosed within the nanofiber, the color change capable of reacting with a specific gas in the air The exposure of the dye material to the surface is limited, and the sensitivity of the color change is lowered.

Experimental Example  1. The above- Example  1, the hydrophilic particles and the color-changing dye material Concluded  Polymer composite nanofiber With membrane Comparative Example  1 < / RTI > Color change  The dye material Concluded  Polymer composite nanofiber The membrane  Detection of hydrogen sulfide gas Color change  Character rating

In order to evaluate the color change characteristics of the hydrogen sulfide gas, the color change membrane sensors obtained through the above Example 1 and Comparative Example 1 were directly exposed to the hydrogen sulfide gas while adjusting the concentration and time of the hydrogen sulfide gas in a high- The color change characteristics are evaluated by exposure.

FIG. 10 is a graph showing the relationship between the weight ratio of the polymer matrix and the color change dye material (lead (II) acetate) prepared in Example 1 and Comparative Example 1, (Al ₂ O ₃ ) is contained in an amount of 15 wt%, 30 wt% and 60 wt% based on the polymer matrix weight ratio, and the color change dye material (lead (II) acetate) Color change sensors are directly exposed to hydrogen sulfide gas under the conditions of 0 ppm, 1 ppm 30 seconds, 1 ppm 1 minute, and 5 ppm 1 minute, respectively.

Color change The image shows the scanned image of each sample after exposure. As the gas concentration and exposure time are increased, the degree of color change gradually increases. In addition, it can be confirmed that the color change becomes thicker as the weight ratio of the hydrophilic particles increases compared to the sample in which the hydrophilic particles are not contained. Thus, the moisture in the air can be adsorbed under the above measurement conditions and the reactivity of the hydrogen sulfide gas and the lead acetate The height can demonstrate the effect of hydrophilic particles.

FIG. 11 is a graph showing the results of colorimetric image analysis of the color change image shown in FIG. 10 for 1 ppm 30 seconds, 1 ppm 1 minute, and 5 ppm 1 minute (RGB variation amount) when the hydrogen sulfide is directly exposed.

When the sample was exposed to hydrogen sulfide gas at 1 ppm for 30 seconds, the sample without hydrophilic particles showed an RGB variation of 22, whereas when the hydrophilic particle contained 60 wt% relative to the polymer weight, the RGB variation was 53, which was about 2.4 times It can be confirmed that the color change sensitivity is increased. Similarly, when the samples were exposed to hydrogen sulfide gas at 1 ppm for 1 minute and 5 ppm for 1 minute, in the case of a sample containing 60 wt% of hydrophilic particles relative to the weight of the polymer, 1.7 times and 1.3 times It can be confirmed that the change sensitivity is improved. The difference in sensitivity enhancement varies depending on the measurement conditions of the hydrogen sulfide gas. However, as the hydrophilic particles (Al ₂ O ₃ ) are included, the color change sensitivity increase effect can be quantitatively determined.

FIG. 12 is a graph showing the results of FIG. 10 and FIG. 11. As shown in FIGS. 10 and 11, hydrophilic particles (Al ₂ O ₃ ) having the best color change characteristics among the nanofiber membrane gas sensor members obtained in Example 1, 10%, 20%, 30%, 40%, 50%, and 50%, respectively, in 5 ppm hydrogen sulfide gas with 300 wt% of the color change dye material (lead (II) acetate) And 60 seconds, respectively.

As shown in FIG. 12, it can be seen that the degree of color change becomes clearer as the exposure time becomes longer. The samples exposed to 5 ppm hydrogen sulfide gas for 10 seconds can be visually confirmed. Thus, a gas-indicating composite polymer nanofiber membrane having a hydrophilic particle and a color-changing dye material bonded to the 1-dimensional nanofiber structure The superiority of the color change sensor can be confirmed.

Experimental Example  2. Example 2 (including high temperature agitation and quench process)  The hydrophilic particles and Color change  The dye material Concluded  Polymer composite nanofiber With membrane Comparative Example 2 (including high temperature agitation and quench process)  Hydrophilic particles are not included Color change  Only the dye material Concluded  Polymer composite nanofiber The membrane  Detection of hydrogen sulfide gas Color change  Character rating

In order to evaluate the color change characteristics of the hydrogen sulfide gas, the nanofiber membrane color change sensors obtained through the above Example 2 and Comparative Example 2 (including the high temperature stirring and quenching process) were exposed to hydrogen sulfide gas in a high humidity environment of 80% The color change characteristics for the hydrogen sulfide gas can be evaluated while adjusting the exposure concentration and time.

FIG. 13 is a graph showing the results of a comparison between a nanofiber membrane obtained by binding the color change dye material (lead (II) acetate) containing hydrophilic particles prepared in Example 2 and Comparative Example 2 to a polymer matrix weight ratio of 300 wt% (Al ₂ O ₃ ) is contained in an amount of 15 wt%, 30 wt% and 60 wt% based on the polymer matrix weight ratio, and the color change dye material (lead (II) acetate) Color change sensors are directly exposed to hydrogen sulfide gas under the conditions of 0 ppm, 1 ppm 30 seconds, 1 ppm 1 minute, and 5 ppm 1 minute, respectively.

It shows the scanned image of each sample after color change exposure. As the gas concentration and exposure time are increased, the degree of color change gradually becomes thicker. In addition, it can be confirmed that the color change becomes thicker as the weight ratio of the hydrophilic particles increases compared to the sample not containing the hydrophilic particles. Through this, it is possible to adsorb the moisture in the air under the above measurement conditions and to measure the reactivity of the hydrogen sulfide gas and the lead acetate The height can demonstrate the effect of hydrophilic particles.

14 is a graph showing the relationship between the color change scan image and the color change scan image in terms of 1 ppm for 30 seconds, 1 ppm for 1 minute, and 5 ppm for the color change scan image shown in the chart of Fig. 13 for quantitative analysis of the clearer color change of the scan image shown in Fig. The degree of change of color change (RGB change amount) when direct exposure to hydrogen sulfide is shown. The RGB variation analysis graph shows that hydrophilic particles (Al ₂ O ₃ ) are contained in an amount of 60 wt% based on the polymer matrix weight ratio, and color change dye material (lead (II) acetate) wt% bound nanofiber membrane.

Specifically, in the case of a sample containing hydrophilic particles of 60 wt% relative to the weight ratio of the polymer, 1 ppm 30 seconds, 1 ppm 1 minute, and 5 ppm 1 minute were directly exposed to the hydrogen sulfide gas, And the change amount is increased by 3 times, 1.5 times and 1.2 times, respectively. Likewise, although the difference in degree of color change varies depending on each measurement condition, it is confirmed by quantitative numerical value that the degree of color change of the sample containing the hydrophilic particle increases, and the effect can be known.

FIG. 15 is a graph showing the relationship between the weight ratio of hydrophilic particles (Al ₂ O ₃ ) and the color change dye material (lead (II) acetate) 10, 20, 30, 40, 50, and 60 seconds in the 5 ppm hydrogen sulfide gas of 300 wt% bound nanofiber membrane relative to the polymer matrix weight ratio.

As shown in FIG. 15, the longer the exposure time is, the more the degree of color change to brown becomes more clear. It can be seen that the sample exposed to 5 ppm of hydrogen sulfide gas for a very short time of 10 seconds can also be visually confirmed. As a result, the hydrophilic particles and the color change dye material are combined with the 1-dimensional nanofiber structure The superiority of the gas-indicating composite polymer nanofiber membrane color-change sensor can be confirmed.

16 is a graph showing the relationship between the hydrogen sulfide detection color change sensor commercialized by Johnson Co., which is commercially available, and the hydrophilic particles in Example 1 and Example 2 prepared by Method 1 and Method 2, A graph showing the difference in the degree of color change (RGB variation) when one minute of exposure to 1 ppm of hydrogen sulfide gas in a nanofiber membrane color sensor in which a transition dye material (lead (II) acetate) is bound to a polymer matrix weight ratio of 300 wt% .

For the samples prepared by Method 1 (including ball milling) and Method 2 (including high temperature agitation and quenching) compared to commercially available commercial samples (Johnson sample), the RGB change rates before hydrogen sulfide gas exposure were 2.3 times and 1.7 It is possible to confirm that the color change characteristic is much higher than that of blue color. The comparison of color change sensing ability with commercially available samples shows that the nanofiber structure using electrospinning gives a structural effect on the structure and hydrogen sulfide detection through hydrophilic induction by binding hydrophilic particles.

Although the present invention has been described in detail in the case of hydrogen sulfide, it can be applied to fabrication of color change gas sensor nanofiber membranes for various gases as well as hydrogen sulfide through other combinations of dyes and hydrophilic particles.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments described in the present invention are not intended to limit the technical spirit of the present invention, but are intended to be illustrative and not restrictive. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents thereof should be construed as being included in the scope of the present invention.

Claims (31)

A color change dye material that changes color by reacting with a specific gas molecule, and a polymer nanofiber that binds hydrophilic particles that induce adsorption of moisture in the air,
Wherein the polymer nanofibers have a three-dimensional network structure
Wherein the polymer nanofiber membrane color change sensor is characterized by: The method according to claim 1,
The three-dimensional network structure is a three-dimensional porous membrane structure in which the polymer nanofibers having a one-dimensional structure are randomly intertwined with each other or stacked in a predetermined direction
Wherein the polymer nanofiber membrane color change sensor is characterized by: The method according to claim 1,
The hydrophilic particles may be oxide particles having polarity characteristics
Wherein the polymer nanofiber membrane color change sensor is characterized by: The method according to claim 1,
The hydrophilic particles have a diameter ranging from 2 nm to 500 nm
Wherein the polymer nanofiber membrane color change sensor is characterized by: The method according to claim 1,
The hydrophilic particles are _{antimony tetroxide (Sb 2 O 4)} , cobalt (II, III) oxide (Co 3 O 4), iron (II, III) oxide (Fe 3 O 4), lead (II, IV) oxide (Pb _{3 O 4), manganese (II} , III) oxide (Mn 3 O 4), silver (I, III) oxide (Ag 2 O 2), triuranium octoxide (U 3 O 8), copper (I) oxide (Cu 2 _{O), dicarbon monoxide (C 2} O), dichlorine monoxide (Cl 2 O), lithium oxide (Li 2 O), potassium oxide (K 2 O), rubidium oxide (Rb 2 O), silver oxide ([Ag 2 O ), thallium (I) oxide ( Tl 2 O), sodium oxide (Na 2 O), aluminium (II) oxide (AlO), barium oxide (BaO), beryllium oxide (BeO), cadmium oxide (CdO), calcium oxide (II) oxide (FeO), lead (II) oxide (PbO), magnesium (II) oxide (CuO), chromium (II) oxide (CrO), cobalt (SrO), sulfur monoxide (SO), disulfur dioxide (S ₂ O), and sulfur dioxide (H ₂ O) ₂ ), tin (II) oxide (SnO), titanium (II) oxide, vanadium (II) oxide, zinc oxide (ZnO), aluminum oxide _{Al 2 O 3), antimony trioxide} (Sb 2 O 3), arsenic trioxide (As 2 O 3), bismuth (III) oxide (Bi 2 O 3), boron trioxide (B 2 O 3), chromium (III) oxide _{(Cr 2 O 3), dinitrogen} trioxide (N 2 O 3), erbium (III) oxide (Er 2 O 3), gadolinium (III) oxide (Gd 2 O 3), gallium (III) oxide (Ga 2 O 3 ), holmium (III) oxide ( Ho 2 O 3), indium (III) oxide (In 2 O 3), iron (III) oxide (Fe 2 O 3), lanthanum oxide (La 2 O 3), lutetium (III _{) oxide (Lu 2 O 3)} , nickel (III) oxide (Ni 2 O 3), phosphorus trioxide (P 4 O 6), promethium (III) oxide (Pm 2 O 3), rhodium (III) oxide (Rh 2 _{O 3), samarium (III)} oxide (Sm 2 O 3), scandium oxide (Sc 2 O 3), terbium (III) oxide (Tb 2 O 3), thallium (III) oxide (Tl 2 O 3), thulium _{(III) oxide (Tm 2 O} 3), titanium (III) oxide (Ti 2 O 3), tungsten (III) oxide (W 2 O 3), vanadium (III) oxide (V 2 O 3), ytterbium (III _{) oxide (Yb 2 O 3)} , yttrium (III) oxide (Y 2 O 3), cerium (IV) oxide (CeO 2), chlorine dioxide (ClO 2), chromium (IV) oxide (CrO 2), dinitrogen tetroxi _{de (N 2 O 4),} germanium dioxide (GeO 2), hafnium (IV) oxide (HfO 2), lead dioxide (PbO 2), manganese dioxide (MnO 2), plutonium (IV) oxide (PuO 2), rhodium _{(IV) oxide (RhO 2)} , ruthenium (IV) oxide (RuO 2), selenium dioxide (SeO 2), silicon dioxide (SiO 2), sulfur dioxide (SO 2), tellurium dioxide (TeO 2), thorium dioxide ( _{ThO 2), tin dioxide (SnO} 2), titanium dioxide (TiO 2), tungsten (IV) oxide (WO 2), uranium dioxide (UO 2), vanadium (IV) oxide (VO 2), zirconium dioxide (ZrO 2 _{), antimony pentoxide (Sb 2 O} 5), arsenic pentoxide (As 2 O 5), dinitrogen pentoxide (N 2 O 5), niobium pentoxide (Nb 2 O 5), phosphorus pentoxide (P 2 O 5), tantalum pentoxide ( Ta ₂ O ₅ ), _{vanadium (V) oxide (V 2} O 5), chromium trioxide (CrO 3), molybdenum trioxide (MoO 3), rhenium trioxide (ReO 3), selenium trioxide (SeO 3), sulfur trioxide (SO 3), tellurium trioxide ( _{TeO 3), tungsten trioxide (WO} 3), uranium trioxide (UO 3), xenon trioxide (XeO 3), manganese heptoxide (Mn 2 O 7), rhenium (VII) oxide (Re 2 O 7), technetium (VII) _{oxide (Tc 2 O 7),} osmium tetroxide (OsO 4), ruthenium tetroxide (RuO 4), xenon tetroxide (XeO 4), iridium tetroxide (IrO 4), is to use at least one of hassium tetroxide (HsO ₄₎
Wherein the polymer nanofiber membrane color change sensor is characterized by: The method according to claim 1,
When the color-changing dye material reacts with a specific gas molecule, it changes the frequency of the wavelength within the visible light region, changes the frequency of the outside wavelength in the visible light region, changes the frequency of the wavelength inside the visible light region, Containing material that exhibits color change characteristics due to
Wherein the polymer nanofiber membrane color change sensor is characterized by: The method according to claim 1,
The color change dye material is lead (II) acetate (Pb ( CH 3 COO) 2), iron (II) acetate (Fe (CH 3 COO) 2), nickel (II) acetate (Ni (CH 3 COO) 2) , copper (II) acetate (Cu (CH 3 COO) 2), cadmium acetate (Cd (CH 3 COO) 2), cobalt (II) acetate (Co (CH 3 COO) 2), manganese (II) acetate (Cu _{(CH 3 COO) 2),} bismuth (III) acetate (Co (CH 3 COO) 3), silver (I) acetate (Ag (CH 3 COO)), silver nitride (AgNO 3), o-tolidine, m- tolidine, bromophenol blue + TBAH, methyl red + TBAH, thymol blue + TBAH, fluorescein, bromocresol purple, bromophenol red, LiNO ₃ , 5-10-15-20-tetraphenylporphyrinatozinc (2,4,6-trimethylphenyl) porphyrinatozinc (II)
Wherein the polymer nanofiber membrane color change sensor is characterized by: The method according to claim 1,
The color-changing dye material may have a diameter ranging from 1 nm to 1 占 퐉
Wherein the polymer nanofiber membrane color change sensor is characterized by: The method according to claim 1,
The hydrophilic particles and the color change dye material are uniformly bound to the inside and the surface of the polymer nanofiber
Wherein the polymer nanofiber membrane color change sensor is characterized by: The method according to claim 1,
The color-changing dye material may be lead acetate (lead (II) acetate) which reacts with hydrogen sulfide (H ₂ S) gas to exhibit color change
Wherein the polymer nanofiber membrane color change sensor is characterized by: The method according to claim 1,
Wherein the polymer nanofibers are formed by electrospinning a polymer solution containing the hydrophilic particles and the color change dye material
Wherein the polymer nanofiber membrane color change sensor is characterized by: The method according to claim 1,
The polymer nanofiber may have a diameter in the range of 100 nm to 10 탆
Wherein the polymer nanofiber membrane color change sensor is characterized by: The method according to claim 1,
The weight ratio of the hydrophilic particles is in the range of 0.1 to 100 wt% based on the weight of the polymer used in the polymer nanofibers
Wherein the polymer nanofiber membrane color change sensor is characterized by: The method according to claim 1,
The weight ratio of the color-changing dye material is in the range of 0.1 to 400 wt% with respect to the weight of the polymer used in the polymer nanofiber
Wherein the polymer nanofiber membrane color change sensor is characterized by: The method according to claim 1,
The polymer constituting the polymer nanofiber may be selected from the group consisting of polypropyl alcohol (PPFA), polymethyl methacrylate (PMMA), polyacrylic copolymer, polyvinyl acetate (PVAc), polyvinyl acetate copolymer, Polystyrene (PS), polyvinylpyrrolidone (PVP), polystyrene copolymer, polyethylene oxide (PEO), polyethylene oxide copolymer, polycarbonate (PC), polyvinyl chloride ), Polypropylene oxide copolymer, polycaprolactone, polyvinyl fluoride, polyvinylidene fluoride (PVDF), polyvinylidene fluoride copolymer, polyimide, poly (PAN, polyacrylonitrile), polyethylene terephthalate (PET), polypropylene oxide (PPO, polypropy lene oxide, polyvinyl alcohol (PVA), styrene acrylonitrile (SAN), polycarbonate (PC), polyaniline (PANI), polypropylene (PP) And at least one of polyethylene (PE, polyethylene)
Wherein the polymer nanofiber membrane color change sensor is characterized by: The method according to claim 1,
The composite polymer nanofiber membrane color change sensor may be used to detect the presence of environmentally harmful gases (H ₂ S, SO _x , NO _x , CO _x ) or biological indicator gases (CH ₃ COCH ₃ , C ₂ H ₅ OH, C ₆ H ₅ CH ₃ )
Wherein the polymer nanofiber membrane color change sensor is characterized by: A step of preparing an electric spinning liquid wherein an electrolytic solution is prepared by mixing a hydrophilic particle and a color change dye material in a polymer solution in which a polymer is dissolved in a solvent;
A nanofiber fabricating step of producing polymer nanofibers having hydrophilic particles and color-changing dye materials bound through an electrospinning process using an electric spinning solution; And
A membrane collection step of collecting the polymer nanofibers in a membrane form on a collecting plate
Wherein the method comprises the steps of: A step of preparing an electric spinning liquid wherein an electrolytic solution is prepared by mixing a hydrophilic particle and a color change dye material in a polymer solution in which a polymer is dissolved in a solvent;
A high-temperature stirring step of dissolving the color-changing dye material contained in the electric spinning solution through a high-temperature stirring process;
A quenching step of producing an electrospinning solution containing a color-changing dye material coagulated with fine crystals through a quenching process;
A nanofiber fabricating step of producing polymer nanofibers having hydrophilic particles and color-changing dye materials bound through an electrospinning process using an electric spinning solution; And
A membrane collection step of collecting the polymer nanofibers in a membrane form on a collecting plate
Wherein the method comprises the steps of: The method according to claim 17 or 18,
The solvent is selected from the group consisting of deionized water, tetrahydrofuran, methanol, isopropanol, formic acid, acetonitrile, nitromethane, (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc), acetic acid, ethanol, acetone, ethylene glycol (EG), dimethyl sulfoxide And at least one of toluene
Wherein the method comprises the steps of: The method according to claim 17 or 18,
The polymer is prepared in a specific solvent in a weight ratio ranging from 0.1 to 90 wt%
Wherein the method comprises the steps of: The method according to claim 17 or 18,
The hydrophilic particles preferably have an average particle size in the range of 2 nm to 500 nm
Wherein the method comprises the steps of: The method according to claim 17 or 18,
The color change dye material may be selected from the group consisting of ball-milling, gyratory crusher, hammer mill, jaw crusher, corn mill, roll crusher, An edge runner, a ring-roll mill, a stamp mill, a rod mill, a screw shear mill, an impact mill, a jet mill, , A top type rubbing machine, a colloid mill and a sonication to have an average particle size in the range of 1 nm to 1 탆
Wherein the method comprises the steps of: 19. The method of claim 18,
The high-
And the color-changing dye material is dissolved by stirring at a temperature higher than the melting point of the color-changing dye material
Wherein the method comprises the steps of: 19. The method of claim 18,
In the quenching step,
The electrical spinning solution containing the color-changing dye material dissolved in the high-temperature stirring step is quenched at a temperature of 25 ° C or lower to recrystallize the color-changing dye material
Wherein the method comprises the steps of: 19. The method of claim 18,
The high-
When lead (II) acetate is used as the color-changing dye material, the lead acetate is liquefied by stirring at a temperature of 75 ° C or higher, which is the melting point of lead acetate
Wherein the method comprises the steps of: 26. The method of claim 25,
In the quenching step,
Liquefied lead acetate is recrystallized by quenching at temperatures below 25 ° C
Wherein the method comprises the steps of: The method according to claim 17 or 18,
In the nanofiber manufacturing step,
Electrospinning of electrospinning solution through an electrospinning process to form polymer nanofibers of one-dimensional structure
Wherein the method comprises the steps of: The method according to claim 17 or 18,
In the nanofiber manufacturing step,
Discharging the electric discharge fluid according to the discharge amount having a range of 0.1 to 500 μl / min
Wherein the method comprises the steps of: The method according to claim 17 or 18,
In the nanofiber manufacturing step,
To form a polymer nanofiber having a one-dimensional structure by applying a voltage of 1 to 50 kV between a syringe and a collecting plate for discharging an electric discharge fluid
Wherein the method comprises the steps of: The method according to claim 17 or 18,
Wherein the membrane collection step comprises:
Forming a polymer nanofiber membrane of constant thickness using a collector plate made of stainless steel, paper, non-woven fabric, or plastic substrate
Wherein the method comprises the steps of: The method according to claim 17 or 18,
Wherein the membrane collection step comprises:
To form a polymer nanofiber membrane having a thickness in the range of 5 to 1000 mu m
Wherein the method comprises the steps of:

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