KR20220152603A - Integrated mold electrode for electrochemical measurement - Google Patents

Abstract

The present invention is to provide an integrated mold electrode for electrochemical analysis, in which a reference electrode, a working electrode, and a relative electrode are integrally molded so that the distance between the electrodes is controlled to be the minimum distance constantly, thereby accurately measuring the electric conductivity or the like of a measurement specimen and remarkably save the measurement specimen, and the electrodes can be kept clean through the reduction of a contaminated area in each electrode and easy cleaning.

Description

Integrated mold electrode for electrochemical analysis {INTEGRATED MOLD ELECTRODE FOR ELECTROCHEMICAL MEASUREMENT}

The present invention relates to an integrated molded electrode for electrochemical analysis, and more particularly, by integrally molding a reference electrode, a working electrode, and a counter electrode, and constantly controlling the distance between each electrode to accurately measure the electrical conductivity of a measurement sample. It relates to an integrally molded electrode for electrochemical analysis that enables measurement.

As is well known, as three major electrodes for precise electrochemical analysis, a reference electrode, a working electrode and a counter electrode are used.

The reference electrode is manufactured in a universal structure including a metal wire, a reference solution, and a porous frit separated from the electrolyte in a glass body, and the working electrode is made of materials such as carbon, platinum, and gold. It is manufactured in a plate-like structure with a diameter of about 3 mm, and the counter electrode is manufactured in a structure including a wire or coil of platinum material corresponding to the area of the working electrode.

The reference electrode, the working electrode, and the counter electrode manufactured in this way are airtightly assembled in the sample case, and at the same time, are immersed in the electrolyte solution, which is a sample to be measured, filled in the sample case.

Therefore, a potential transformer and a computer are connected to the reference electrode, the working electrode and the counter electrode, and data such as current and voltage changes measured by the reference electrode, the working electrode and the counter electrode are processed by the computer.

However, the reference electrode, the working electrode, and the counter electrode are individually manufactured and assembled in the sample case, so there are the following problems.

First, since the utilization of the porous frit included in the reference electrode for each electrolyte is low, organic solvents and basic solvents cannot be used, and it is vulnerable to contamination, and it is difficult to wash contaminants.

Second, since the area of the working electrode is large, an excessive amount of sample (electrolyte solution, etc.) for measurement is inevitably consumed, and unnecessary side reactions occur, resulting in increased data calculation time, and also the area of the counter electrode As it is manufactured with an increased structure, an excessive amount of samples for measurement are inevitably consumed, resulting in an increase in the price of electrode materials and samples.

Third, when each electrode is assembled in a sample case of a limited size, the area of the working electrode and the counter electrode is large, so there is a limit to controlling the distance between each electrode to a minimum, and the contamination area of the electrode increases according to repeated measurement of each electrode. There is a problem that comes with difficulty in cleaning.

The present invention has been devised to solve the above conventional problems, and the reference electrode, the working electrode, and the counter electrode are integrally molded, and the distance between each electrode is constantly controlled to a minimum distance to improve the electrical conductivity of the measurement sample. It provides an integrated molded electrode for electrochemical analysis that not only can accurately measure the etc., but also can greatly reduce the number of samples to be measured, reduce the contamination area of each electrode and maintain the cleanliness of the electrode through easy cleaning. There is a purpose.

In order to achieve the above object, one embodiment of the present invention is: a reference electrode connected to a first metal wire to the lower end of a single wire coated with an insulating layer, and a second metal wire to the lower end of the single wire coated with an insulating layer An integrated molded electrode for electrochemical analysis, characterized in that the connected working electrode and the counter electrode to which the third metal wire is connected to the lower end of the single wire coated with an insulating layer are molded into a molding body in a state where they are separated by a predetermined distance and integrated. provides

The reference electrode includes: a first single wire coated with an insulating layer made of Teflon; A first metal wire made of silver connected to the lower end of the first solid wire by soldering; and a heat-shrinkable tube made of an insulating material wrapped around a portion where the first solid wire and the first metal wire are interconnected by soldering. It is characterized in that it is configured to include.

The working electrode includes: a second single wire coated with an insulating layer made of Teflon; A second metal wire made of platinum connected to the lower end of the second single wire by soldering; and a heat-shrinkable tube made of an insulating material wrapped around a portion where the second solid wire and the second metal wire are interconnected by soldering. It is characterized in that it is configured to include.

The counter electrode includes: a third single wire coated with an insulating layer made of Teflon; A third metal wire made of platinum connected to the lower end of the third single wire by soldering; and a heat-shrinkable tube made of an insulating material wrapped around a portion where the third solid wire and the third metal wire are interconnected by soldering. It is characterized in that it is configured to include.

In particular, the bottom surface of the first metal wire, the bottom surface of the second metal wire, and the bottom surface of the third metal wire are each exposed to the outside to be in contact with the sample while forming the same plane as the bottom surface of the molded body.

The molded body is characterized in that it is an epoxy mixed with resin Poly (Bisphenol A-co-epichlorohydrin) and curing agent 1,3-Phenylenediamine at a weight ratio of 8:2 at 80 °C.

Another embodiment of the present invention in order to achieve the above object is: preparing a hollow tube made of Teflon; sealing the opening on one side of the tube with Teflon tape; inserting a reference electrode, a working electrode, and a counter electrode into the tube while maintaining a predetermined distance therebetween, and then injecting an epoxy mixture solution into the tube so that each electrode is molded into a molded body; and removing the sealed Teflon tape after curing the epoxy, and then polishing the epoxy at the lower end of the molding body to form a bottom surface of the first metal wire as a reference electrode, a bottom surface of the second metal wire as a working electrode, and a third metal wire as a counter electrode. exposing the lower surface to the outside; It provides a method for manufacturing an integral molded electrode for electrochemical analysis, characterized in that it comprises a.

The manufacturing method of the present invention further comprises the step of polishing the bottom surface of the first metal wire, the bottom surface of the second metal wire and the bottom surface of the third metal wire to a glassy phase using an aluminum oxide abrasive.

Accordingly, the electrode exposure area of the reference electrode, the working electrode, and the counter electrode in contact with the sample is determined by the diameters of the first, second, and third metal wires exposed in the same plane as the bottom surface of the molded body.

On the other hand, when the bottom surface of the first metal wire as the reference electrode, the bottom surface of the second metal wire as the working electrode, and the bottom surface of the third metal wire as the counter electrode are coated with contaminants, the contaminants are removed by polishing, or A step of etching and removing the bottom surface may be further performed.

Through the means for solving the above problems, the present invention provides the following effects.

First, since the minimum required amount of sample (electrolyte) required for measurement is only 0.1 ml, the sample can eventually be greatly reduced to 1/5 or less compared to the existing level.

Second, since the area in contact with the sample is limited by the mold body and only the area of each electrode limited to the bottom surface of the first, second, and third metal wires comes into contact with the sample, the sample contact area control of each electrode can be made constant, , and thus reliability and reproducibility of the electrochemical precision analysis of the sample can be secured.

Third, after precise measurement and analysis, even if the surface of each electrode, that is, the bottom surface of the first, second, and third metal wires is contaminated with contaminants, it can be easily removed by polishing with an abrasive or sandpaper, or the surface with contaminants is treated with an etchant or the like. Since it can be easily cleaned by etching, the surface of each electrode can be kept clean during each measurement, and reproducible results can be obtained.

Fourth, the distance between the reference electrode - the working electrode - the counter electrode, that is, the distance between the bottom surfaces of the first, second and third metal wires can be kept constant by means of a molded body made of epoxy material, and the electrical conductivity of the sample is sensitively measured accordingly. good for measurement

Fifth, after the integral molded electrode is sealed and inserted into the container, if the inside of the container needs to be controlled to an oxygen environment according to measurement conditions, the coral environment can be easily created using a gas injection needle.

Sixth, compared to conventional electrodes composed of glass molds, integral molded electrodes are less likely to break because they are cured epoxy molded electrodes.

1 is a cross-sectional view showing an integral molded electrode for electrochemical analysis according to the present invention;
Figure 2 is an enlarged cross-sectional view of the main part of the integral molded electrode for electrochemical analysis according to the present invention;
3 is a bottom view showing an integral molded electrode for electrochemical analysis according to the present invention;
4 is a schematic circuit diagram showing an electrical connection state during electrochemical analysis of an integrated mold electrode according to the present invention;
5 and 6 are bottom views showing the contamination area after use of the integrated molded electrode for electrochemical analysis according to the present invention;
7 is a cross-sectional view showing a state in which an integrated molded electrode according to the present invention is assembled in a sample case for electrochemical analysis.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 to 3 show an integrated molded electrode for electrochemical analysis according to the present invention.

As shown in FIGS. 1 and 2, the integral mold electrode 100 according to the present invention is based on the first metal wire 12 connected to the lower end of the first solid wire 11 coated with the insulating layer 60. The electrode 10 and the working electrode 20 to which the second metal wire 22 is connected to the lower end of the second single wire 21 coated with the insulating layer 60, and the third coated with the insulating layer 60 The counter electrode 30 to which the third metal wire 32 is connected to the lower end of the single wire 31 is integrally molded by the molding body 40 while being maintained at a predetermined minimum distance.

More specifically, the reference electrode 10 is coated with an insulating layer 60 made of Teflon and connected to a measuring device (eg, a potentiometer and a computer), and a conductive first single wire 11, A first metal wire 12 made of silver connected to the lower end of the first single wire 11 by soldering 50, and the first single wire 11 and the first metal wire 12 are soldered 50 ) It is configured to include a heat-shrinkable tube 70 of insulating material wrapped to prevent short-circuiting and detachment from interconnected parts by.

In addition, the working electrode 20 includes a second conductive wire 21 coated with an insulating layer 60 made of Teflon and connected to a measuring device (eg, a potentiometer and a computer), and the second A second metal wire 22 made of platinum connected to the lower end of the disconnected wire 21 by soldering 50, and the second disconnected wire 21 and the second metal wire 22 are connected by soldering 50. It is configured to include a heat-shrinkable tube 70 of an insulating material wrapped around the interconnected parts to prevent short circuit and detachment.

In addition, the counter electrode 30 includes a conductive third single wire 31 coated with an insulating layer 60 made of Teflon and connected to a measuring device (eg, a potentiometer and a computer), and the third A third metal wire 32 made of platinum connected to the lower end of the disconnected wire 31 by soldering 50, and the third disconnected wire 31 and the third metal wire 32 are connected by soldering 50 It is configured to include a heat-shrinkable tube 70 of an insulating material wrapped around the interconnected parts to prevent short circuit and detachment.

For reference, the first, second, and third single wires 11, 12, and 13 refer to individual conductive wires that are not easily bent, unlike twisted-pair wires composed of several easily bent wires.

The first, second, and third single wires 11, 21, and 31 coated by the insulating layer 60 are applied with a larger diameter than the first, second, and third metal wires 12, 22, and 32, It can be applied to one of AWG24, AWG25, AWG26, AWG28, and AWG29 according to the American wire gauge (AWG) standard that defines standardization for wire thickness, and the insulating layer 60 is a Teflon coating layer, and the material of the molding body 40 It serves to prevent disconnection of wire and chemical and thermal changes that occur during curing of phosphorus epoxy.

For reference, the lower the AWG, the thicker the wire, and the higher the AWG, the thinner the wire.

At this time, the diameter of the Teflon-coated portion including the single-wire wire is 1.2 mm or less, and the length is preferably applied at least 1.5 times that of the first, second, and third metal wires.

Preferably, silver ( Ag) wire has a diameter in the range of 0.1 to 1.0 mm, and platinum used as the second metal wire 22 of the working electrode 20 and the third metal wire 32 of the counter electrode 30 ( The diameter of the Pt) wire may be employed to be in the range of 0.002 to 1.0 mm.

More preferably, the diameter of the silver wire used as the first metal wire 11 so that the measurement operation of each electrode can be accurately performed is the second metal wire 22 and the third metal wire 32. It is applied with a larger diameter by about 120% than the diameter of the platinum wire, and the second metal wire 22 and the third metal wire 32 are applied with the same diameter.

On the other hand, the inner diameter of the heat shrinkable tube 70 is larger than the outer diameter of the insulating layer 60 made of Teflon, but less than twice the diameter of the insulating layer 60 is applied.

The molding body 40 is molded to be integral with the reference electrode 10, the working electrode 20, and the counter electrode 30 provided as described above while maintaining a predetermined minimum distance, and resin Poly (Bisphenol A -co-epichlorohydrin) and curing agent 1,3-Phenylenediamine in a weight ratio of 8:2, and an epoxy mixed at 80 °C can be used.

At this time, when the reference electrode 10, the working electrode 20, and the counter electrode 30 are molded with the molding body 40 made of epoxy, the solder 50 connection connecting the single wire and the metal wire is a heat shrinkable tube ( 70), it is possible to easily prevent short-circuiting or detachment of the solder 50 joint that may occur during epoxy curing.

Therefore, when molding by the molding body 40 is completed, the first disconnected wire 11 of the reference electrode 10, the second disconnected wire 21 of the working electrode 20, and the counter electrode 30 The third single wire 31 of ) is in a state where a predetermined length is exposed to the outside through the upper part of the molding body 40 for connection with the measuring device, and in particular, as shown in FIG. 3, the first metal wire 12 ) Including the second metal wire 22 and the bottom surface of the third metal wire 23 is exposed while forming the same plane as the bottom surface of the molding body 40.

Accordingly, the electrode exposed areas of the reference electrode 10, the working electrode 20, and the counter electrode 30 in contact with the sample are the first, second, and third metal wires forming the same plane as the bottom surface of the molding body 40 ( 12, 22, and 32), that is, the diameter of the first, second, and third metal wires 12, 22, and 32 may be determined.

Here, looking at the manufacturing process for the integrated mold electrode of the present invention consisting of the above configuration is as follows.

First, a circular hollow tube made of Teflon material serving as a formwork is prepared.

The tube was cut with a margin of about 15 mm beyond the length of each electrode, and one opening was sealed with Teflon tape.

Subsequently, the reference electrode 10, the working electrode 20, and the counter electrode 30 manufactured as described above are inserted and arranged in the tube while maintaining a predetermined distance, and then the material of the molding body 40 is placed inside the tube. Inject the phosphorus epoxy mixture.

Subsequently, the epoxy curing was performed at 130° C. for 3 hours, stored at room temperature for 5 hours or more, and then the sealed Teflon tape was removed.

Next, the bottom surface of the first, second, and third metal wires 12, 22, and 32 is exposed to the outside by sanding the epoxy at the lower end of the molded body 40, that is, the place where the Teflon tape is removed, and The exposed bottom surface is further polished into a vitreous phase using aluminum oxide abrasives having a diameter of 100, 50, or 5 μm, thereby completing the integrated mold electrode 100 of the present invention.

Accordingly, the electrode exposed areas of the reference electrode 10, the working electrode 20, and the counter electrode 30 in contact with the sample are the first, second, and third exposed areas forming the same plane as the bottom surface of the molding body 40. It may be determined by the bottom surface of the metal wires 12, 22, and 32, that is, the diameters of the first, second, and third metal wires 12, 22, and 32.

Here, referring to FIG. 7 attached to the measurement and use state of the integral molded electrode of the present invention, the following will be described.

First, the integrated mold electrode 100 of the present invention manufactured as described above is inserted into a container 200 filled with a sample solution (electrolyte solution), and the inlet of the container 200 is sealed with a sealing material 202 such as a paraffin film. Seal it.

At this time, as the container 200, a 1 to 3 mL standard vial, which is one of glass containers, may be used.

In addition, when the inside of the container 200 needs to be controlled to an oxygen environment according to measurement conditions, the gas injection needle 204 may pass through the sealing material 202 and be inserted into the container 200 .

As described above, when the integrated mold electrode 100 is inserted into the container 200 filled with the sample solution and sealed and fixed, the bottom surface of the first metal wire 12 of the reference electrode 10 and the first portion of the working electrode 20 A space of 0.1 ml or less is formed between the bottom surface of the second metal wire 22 and the bottom surface of the third metal wire 32 of the counter electrode 30 and the bottom surface of the container 200 .

Therefore, even if only 0.1 ml of sample (electrolyte) is injected into the container 200, measurement is possible without considering electrode wetting, and the minimum amount of sample (electrolyte) required for measurement is only 0.1 ml. , in the end, the sample can be greatly reduced to 1/5 or less compared to the existing one.

Next, the lower end of the integrated mold electrode 100, that is, the first metal wire 12 as the reference electrode 10, the second metal wire 22 as the working electrode 20, and the third metal as the counter electrode 30 In a state where the wires 32 are in contact with each sample, electrochemical analysis is performed on the sample.

For example, as shown in FIG. 4, the first metal wire 12 as the reference electrode 10, the second metal wire 22 as the working electrode 20, and the third metal wire as the counter electrode 30 ( 32) is connected to allow current and voltage application by the first, second, and third single wires 11, 21, and 31 connected to the measuring device, respectively, Volta for measuring the current-potential curve for the sample In a voltammetry experiment, when a voltage is applied while changing to the working electrode compared to the reference electrode, the sample undergoes an electrochemical reaction on the surface of the working electrode. At this time, the flow of electrons consumed or needed can be measured at the counter electrode.

In addition, electrons are supplied or taken from the counter electrode to the working electrode as current so that the sample undergoes an electrochemical reaction such as a galvanostatic reaction on the surface of the working electrode. The difference in chemical energy can be measured as the potential difference between the reference and working electrodes.

In addition, as the area of the counter electrode in contact with the sample (electrolyte) is maintained at a constant area regardless of the sample capacity, reliability and reproducibility of precise analysis can be secured by applying a constant current in the galvanostatic reaction.

In other words, since the result value varies depending on the area of the working electrode where the reaction occurs and the counter electrode that measures electrons during the precise analysis experiment, it is important to control the area of the working electrode and the counter electrode. Although it is composed of individual molded electrodes and controls the electrode area, it is virtually impossible to control the contact area of the counter electrode with the sample (electrolyte) that it touches using a coil or wire, making it difficult to secure reproducibility of current measurement. The area in contact with the silver sample is limited by the mold body, and at the same time, only the electrode area limited to the bottom surface of the first, second, and third metal wires 12, 22, and 32 is in contact with the sample. have.

Meanwhile, during the manufacturing process of the integrated mold electrode 100, the bottom surfaces of the first metal wire 12 as the reference electrode 10 and the second metal wire 22 as the working electrode 20 may be contaminated with contaminants, respectively. , or after measurement of each electrode including a voltammetry experiment and a galvanostatic reaction, as shown in FIG. 5, the first metal wire 12 as the reference electrode 10 and the second as the working electrode 20 Contaminants (reaction byproducts) may be coated on the lower surface of the metal wire 22, respectively, or as shown in FIG. 6, the second metal wire 22 as the working electrode 20 and the third metal wire 22 as the counter electrode 30 Contaminants (reaction by-products) may be coated on the lower surface of each metal wire 32 .

Therefore, the contaminants coated on the bottom surfaces of the first, second, and third metal wires 12, 22, and 32 can be easily removed by polishing with an abrasive such as alumina oxide or sandpaper, or the surface with contaminants can be etched with an etchant or the like. Therefore, it is possible to easily clean it, and eventually, the exposed surface for measurement of each electrode can always be kept clean not only at the time of completion of manufacturing of the integral mold electrode but also during measurement use.

As seen above, the area of the counter electrode and the working electrode including the reference electrode, that is, the bottom area of the first, second, and third metal wires 12, 22, and 32 is about 1/30 to 10 ^-6 times that of conventional commercial electrodes. Since it is small, measurement and analysis of a small amount of samples can be performed quickly compared to conventional commercial electrodes, cost reduction of electrode materials can be expected, and sample consumption can be significantly reduced to 1/5 or less compared to conventional electrodes. and cost can be greatly reduced.

10: reference electrode 11: first single wire
12: first metal wire 20: working electrode
21: second single wire 22: second metal wire
30: counter electrode 31: third single wire
32: third metal wire 40: molding body
50: soldering 60: insulating layer
70: heat shrinkable tube 100: integral molded electrode
200: container 202: sealing material
204: gas injection needle

Claims (10)

The reference electrode to which the first metal wire is connected to the lower end of the single wire coated with the insulating layer, the working electrode to which the second metal wire is connected to the lower end of the single wire coated with the insulating layer, and the lower end of the single wire coated with the insulating layer An integrated molded electrode for electrochemical analysis, characterized in that the counter electrode to which the third metal wire is connected is molded into a molded body in a state of being separated by a predetermined distance and integrated.
The method of claim 1,
The reference electrode is:
A first single wire coated with an insulating layer made of Teflon;
A first metal wire made of silver connected to the lower end of the first solid wire by soldering; and
A heat-shrinkable tube made of an insulating material wrapped around a portion where the first solid wire and the first metal wire are interconnected by soldering (50);
An integrated molded electrode for electrochemical analysis, characterized in that configured to include.
The method of claim 1,
The working electrode is:
A second single wire coated with an insulating layer made of Teflon;
A second metal wire made of platinum connected to the lower end of the second single wire by soldering; and
A heat-shrinkable tube made of insulating material wrapped around a portion where the second single wire and the second metal wire are interconnected by soldering;
An integrated molded electrode for electrochemical analysis, characterized in that configured to include.
The method of claim 1,
The counter electrode is:
A third single wire coated with an insulating layer made of Teflon;
A third metal wire made of platinum connected to the lower end of the third single wire by soldering; and
A heat-shrinkable tube made of insulating material wrapped around a portion where the third single wire and the third metal wire are interconnected by soldering; An integrated molded electrode for electrochemical analysis, characterized in that configured to include.
The method of claim 1,
The bottom surface of the first metal wire, the bottom surface of the second metal wire, and the bottom surface of the third metal wire are respectively exposed to the outside to be in contact with the sample while forming the same plane as the bottom surface of the molded body for electrochemical analysis Integral molded electrode.
The method of claim 1,
The molded body is an integral mold electrode for electrochemical analysis, characterized in that the epoxy mixed with resin Poly (Bisphenol A-co-epichlorohydrin) and curing agent 1,3-Phenylenediamine at a weight ratio of 8: 2 at 80 ° C.
Preparing a hollow tube made of Teflon;
sealing the opening on one side of the tube with Teflon tape;
inserting and disposing a reference electrode, a working electrode, and a counter electrode in the tube while maintaining a predetermined distance therefrom, and then injecting an epoxy mixture into the tube so that each electrode is molded into a molded body; and
After the epoxy is cured, the sealed Teflon tape is removed, and then the epoxy at the lower end of the molding body is polished to form the bottom surface of the first metal wire as a reference electrode, the bottom surface of the second metal wire as a working electrode, and the third metal wire as a counter electrode. exposing the lower surface to the outside;
Method for manufacturing an integral molded electrode for electrochemical analysis comprising a.
The method of claim 7,
Further comprising the step of polishing the bottom surface of the first metal wire, the bottom surface of the second metal wire and the bottom surface of the third metal wire to a glassy phase using an aluminum oxide abrasive, characterized in that it further comprises an integral mold electrode for electrochemical analysis. manufacturing method.
The method of claim 7,
Electrochemical analysis characterized in that the electrode exposure area of the reference electrode, the working electrode and the counter electrode in contact with the sample is determined by the diameters of the first, second and third metal wires exposed in the same plane as the bottom surface of the molding body Method for manufacturing an integral molded electrode for
The method of claim 7,
When the bottom surface of the first metal wire as the reference electrode, the bottom surface of the second metal wire as the working electrode, and the bottom surface of the third metal wire as the counter electrode are coated with contaminants, the contaminants are removed by polishing, or each bottom surface with contaminants is removed. A method of manufacturing an integral mold electrode, characterized in that the step of etching and removing is further progressed.

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