KR102155775B1 - Rhodamine-based plastic optical fiber mercury sensor - Google Patents

Abstract

The present invention relates to a rhodamine-based plastic optical fiber mercury sensor. According to the present invention, a hole communicating with the outside is formed in the center portion in the longitudinal direction, and the hole portion is immersed in the aqueous solution to be measured, and the plastic optical fiber into which light of the set wavelength band is incident on one end, and located on the optical path The aqueous solution includes a rhodamine derivative inserted into the hole of the plastic optical fiber so as to be inserted and mounted, and the aqueous solution based on the light transmittance observed from the light output to the other end through the rhodamine derivative after being incident on one end of the plastic optical fiber. It provides a rhodamine-based plastic fiber optic mercury sensor with mercury-resistant sensing.
According to the present invention, when a plastic optical fiber sensor containing a rhodamine derivative having high light-sensitive properties is implemented and light is irradiated at one end, mercury is more effectively detected in an aqueous solution environment based on the light transmittance observed at the other end. It provides the advantage of being able to measure mercury concentration quickly and accurately.

Description

Rhodamine-based plastic optical fiber mercury sensor

The present invention relates to a rhodamine-based plastic optical fiber mercury sensor, and more particularly, to a rhodamine-based plastic optical fiber mercury sensor using a rhodamine derivative to measure the mercury concentration in an aqueous solution environment.

Mercury is a heavy metal that is harmful to the human body, and when introduced into the body, it is very fatal to the human brain, central nerves, kidneys, liver, etc. It causes movement disorders, speech disorders, and paralysis. In order to prevent mercury harm in advance, the detection of dissolved mercury in water is becoming very important.

The conventional mercury detection technique using a rhodamine derivative uses a color change response characteristic that changes from colorless to pink due to the opening of a spirolactam ring when rhodamine binds to mercury ions.

However, in the case of such a color change-dependent measurement method, there is a limit to the accurate detection of the mercury concentration, and there is a need to further improve response speed and sensitivity. Therefore, a new detection technique using the high photosensitive properties of rhodamine derivatives is required.

The technology behind the present invention is disclosed in Korean Patent Registration No. 1079315 (announced on 2011.11.04).

An object of the present invention is to provide a rhodamine-based plastic optical fiber mercury sensor that can more effectively detect mercury in an aqueous solution environment by implementing a plastic optical fiber sensor with a rhodamine derivative inserted therein.

In the present invention, a hole communicating with the outside is formed in the center portion in the longitudinal direction, and the hole portion is immersed in an aqueous solution to be measured, and a plastic optical fiber in which light of a set wavelength band is incident at one end, and located on the optical path The aqueous solution includes a rhodamine derivative inserted into the hole of the plastic optical fiber so as to be inserted and mounted, and the aqueous solution based on the light transmittance observed from the light output to the other end through the rhodamine derivative after being incident on one end of the plastic optical fiber. It provides a rhodamine-based plastic fiber optic mercury sensor with mercury-resistant sensing.

In addition, as the concentration of mercury in the aqueous solution increases, the rhodamine derivative absorbs more light, and the light transmittance may be observed to be a lower value.

In addition, the set wavelength band may have a range of 520 to 540 nm.

In addition, the plastic optical fiber mercury sensor, a light emitting unit for incidence of the light of the set wavelength band to one end of the plastic optical fiber, a light receiving unit for receiving light output to the other end of the plastic optical fiber, and the light transmittance from the received light It may further include a measuring unit that measures and provides whether or not mercury is detected and a corresponding concentration value based on the light transmittance.

In addition, the light emitting unit, the light receiving unit, and the measurement unit may correspond to an LED light source, a camera, and a signal processing unit provided in a user terminal, and the user terminal may output whether the mercury is detected and a concentration value on the screen. have.

In addition, the plastic optical fiber mercury sensor may further include a support formed of a transparent material including Teflon or silicon, and fixed to the inside of the hole while supporting the rhodamine derivative.

In addition, the hole is formed in an elongated shape parallel to the longitudinal direction of the plastic optical fiber, and the rhodamine derivative is inserted so as to be biased in an edge region located in the direction of light out of both edges of the hole, The aqueous solution may be filled on the remaining empty space of the hole.

In addition, a plurality of holes may be formed at predetermined intervals along the length direction of the plastic optical fiber.

According to the present invention, when a plastic optical fiber sensor containing a rhodamine derivative having high light-sensitive properties is implemented and light is irradiated at one end, mercury is more effectively detected in an aqueous solution environment based on the light transmittance observed at the other end. It provides the advantage of being able to measure mercury concentration quickly and accurately.

1 is a view showing the configuration of a plastic optical fiber mercury sensor according to an embodiment of the present invention.
2 is a diagram showing the result of measuring the absorption of light irradiated to the rhodamine derivative for each wavelength.
3 is a view showing the result of measuring the light transmittance according to the concentration of mercury in an aqueous solution using FIG. 1.
4 is a diagram showing in detail a hole formed in the plastic optical fiber of FIG. 1.
5 is a view showing a state in which a rhodamine derivative is inserted into a hole of the plastic optical fiber of FIG. 4.
6 is a view showing a state of processing a hole in the plastic optical fiber of FIG.
7 is a diagram illustrating a modified example of FIG. 5.
8 is a diagram showing an application example of FIG. 1 using a user terminal.

Then, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement the present invention.

1 is a view showing the configuration of a plastic optical fiber mercury sensor according to an embodiment of the present invention.

As shown in Figure 1, the plastic optical fiber mercury sensor 100 according to an embodiment of the present invention is a plastic optical fiber 110 (POF; Plastic Optical Fiber), rhodamine derivatives 120 (Rhodamine derivatives), light emitting unit 130 ), a light receiving unit 140, and a measuring unit 150.

The plastic optical fiber 110 is formed with a hole 111 communicating with the outside in a central portion in the longitudinal direction. These holes 111 are formed to penetrate in a direction perpendicular to the longitudinal direction of the plastic optical fiber 110 and may be processed by a drilling machine. Of course, accordingly, the hole 111 may vertically penetrate the core of the plastic optical fiber 110.

The rhodamine derivative 120 is inserted and mounted inside the hole 111 of the plastic optical fiber and is thus positioned on the optical path of the plastic optical fiber 110.

Methods for preparing rhodamine derivatives have been known in various ways, and the synthesized rhodamine derivatives may be coated through a standardized sol-gel method. Of course, the rhodamine derivative 120 may use a known product, and may be inserted or mounted on the object in a more diverse manner.

Synthesis examples of rhodamine derivatives are as follows. After dissolving 0.958 g (2 mmol) of rhodamine in 20 ml of ethanol at 70° C., 0.67 ml (10 mmol) of ethylene diamine was added and refluxed for 20 hours or more until the fluorescence of the mixture disappears. After standing to cool at room temperature, the precipitated mixture is filtered, and the remaining product is washed with cold ethanol to remove impurities. Finally, the precipitates are collected and added to the Acetonitrile solvent to form recrystallization to form the synthetic derivative N-(Rhodamine)-lactam ethylene diamine, which is a mercury sensing substance.

The synthetic derivative is mixed with the solution. In the sol-gel method, the solution composition ratio is Derivative (synthetic derivative): TMOS (Tetramethyl Orthosilicate): MTMS (Trimethoxy Methylsilane): Ethanol: H2O = 0.048 g: 24 ml: 6 ml: 30 ml: 7.5 ml, which is stirred for 2 hours and coated. . Here, TMOS is a precursor material and distilled water as a solvent is used as a hydrolyzing agent so that evaporation occurs slowly during coating. MTMS improves the adhesion of chemical bonds between the rhodamine derivative and the object, and ethanol uniformly mixes the solution.

In an embodiment of the present invention, a part of the length direction of the optical fiber including the hole 111 portion is immersed on the aqueous solution to be measured, as shown in FIG. 1 for mercury measurement in an aqueous solution environment. Accordingly, the rhodamine derivative 120 inserted into the hole 111 is exposed to the aqueous solution to react.

In most of the existing cases, mercury is detected by using the color change that is expressed when the rhodamine derivative reacts with the mercury concentration, but in the embodiment of the present invention, the light incident on the plastic optical fiber passes through the rhodamine derivative. Mercury is detected and measured based on its permeability.

Specifically, in the embodiment of the present invention, light in the set wavelength range is incident on one end of the plastic optical fiber 110. Light incident through one end of the plastic optical fiber 110 is transmitted to the other end through the rhodamine derivative 120.

Here, as the set wavelength band, a wavelength in the range of 520 to 540 nm, which is shown to have excellent light absorption characteristics in the rhodamine derivative 120, may be used. In the case of FIG. 1, among them, a wavelength of 532 nm close to the peak value is used. The basis will be described later through FIG. 2.

2 is a diagram showing the result of measuring the absorption of light irradiated to the rhodamine derivative for each wavelength. To measure the absorption, as shown in Table 1 below, three types of rhodamine derivatives (Rhodamine 6G) having different purity (A, B, C) were used. A and B types are domestic and C types are foreign.

Type Purity Supplier A 99% Sigma Aldrich B 95% Avention C 90% Avention

Each of the graphs A, B, and C shown in FIG. 2 shows the results of measuring the absorption of the three rhodamine derivatives in Table 1. Absorbance was measured using a spectrometer. In each graph, the horizontal axis represents the concentration of mercury in the aqueous solution, and the vertical axis represents the absorption.

From the results of FIG. 2, it can be seen that all three types of Rhodamine 6G show the highest absorbance at about 530 nm, and the absorbance increases as the concentration of mercury increases. The foreign-made type A shows the best sensitivity, but the price is high, so in this embodiment, a plastic optical fiber sensor was manufactured using the second domestic-made type B, which has the highest sensitivity.

In this embodiment of the present invention, mercury sensing is performed based on the light transmittance observed from the light output to the other end through the rhodamine derivative 120 after being incident on one end of the plastic optical fiber 110.

As the mercury concentration in the aqueous solution of FIG. 1 increases, the rhodamine derivative 120 absorbs more light, so that the light transmittance is observed to be a lower value. That is, the higher the mercury concentration in the aqueous solution, the lower the light transmittance of the rhodamine derivative 120.

3 is a view showing the result of measuring the light transmittance according to the concentration of mercury in an aqueous solution using FIG. 1. In FIG. 3, the horizontal axis represents the concentration of mercury, and the vertical axis represents the light transmittance.

From the results of FIG. 3, it can be seen that the higher the concentration of mercury, the lower the measured value of the light transmittance. This is believed to be because the rhodamine derivative absorbs a greater amount of light when the concentration of mercury is high. If the observed light transmittance by mercury concentration is pre-established in the database, the mercury concentration value in the aqueous solution to be measured can be quickly and accurately provided by measuring the light transmittance later.

In FIG. 1, the light-emitting unit 130 is disposed to face one end of the plastic optical fiber 110, and generates light to be incident on one end of the plastic optical fiber. In the case of this embodiment, as shown in FIG. 1, light having a wavelength of 532 nm was used. The light-emitting unit 130 may be implemented as an LED or a laser diode (LD).

The light-receiving unit 140 is disposed to face the other end of the plastic optical fiber 110 and receives light output to the other end of the plastic optical fiber 110. The light receiving unit 140 may be implemented as a camera, a photodiode (PD), or the like.

The measurement unit 150 measures light transmittance from the received light, and provides whether or not mercury is detected and a corresponding concentration value based on the light transmittance. The measurement unit 150 may correspond to a PC or a user terminal. Of course, the measurement unit 150 may be configured integrally with the light receiving unit 140. The measurement unit 150 may provide whether or not mercury is detected by referring to previously established data, and when mercury is detected, may also provide a concentration value.

FIG. 4 is a view showing in detail a hole formed in the plastic optical fiber of FIG. 1, and FIG. 5 is a view showing a state in which a rhodamine derivative is inserted into the hole of the plastic optical fiber of FIG. 4.

In FIGS. 4 and 5, the upper and lower drawings respectively represent a front view and a plan view. 4 and 5, it can be seen that a long hole 111 is formed parallel to the length direction of the plastic optical fiber 110. Of course, a plurality of holes 111 may be formed at predetermined intervals along the length direction, so that the rhodamine derivative 120 may be inserted for each hole 111.

6 is a view showing a state of processing a hole in the plastic optical fiber of FIG. In the case of the embodiment of the present invention, using a drilling machine with a plastic optical fiber 110 fixed on a bias and an end mill type drilling bit with a diameter of 0.6 mm is used, the size is 3 mm in width and 0.65 mm in length toward the center of the diameter. The hole 111 was machined. As the hole 111 is processed, a part of the core, which is a path of light in the optical fiber, is opened. The hole 111 has a rectangular shape that is long left and right, and rounds are processed at the corners corresponding to the diameter of the drilling bit. In addition, the used plastic optical fiber 110 is manufactured by Toray, which has a core refractive index of 1.49, a cladding refractive index of 1.41, and an outer diameter of 1.5 mm (core diameter: 1.48 mm, cladding diameter: 0.02 mm). I did.

As shown in FIG. 5, the rhodamine derivative 120 is inserted and installed so as to be biased in one edge region of the hole 111 in the direction in which light exits. Accordingly, when immersed in the aqueous solution, the aqueous solution is filled in the remaining empty space S of the hole 111 and the rhodamine derivative 120 reacts with the aqueous solution.

7 is a diagram illustrating a modified example of FIG. 5. In the case of FIG. 7, a support 160 is added that is inserted into the hole 111 while supporting the rhodamine derivative 120 to stably fix the position of the rhodamine derivative 120 inside the hole 111 Shows the appearance.

In this case, the support 160 may be formed of a transparent material including Teflon or silicon so as not to affect optical properties. Further, the rhodamine derivative 120 may be dip-coated on one surface of the support 160 or in a predetermined groove by a sol-gel method.

8 is a diagram showing an application example of FIG. 1 using a user terminal. FIG. 8 is an arrangement of both ends of the plastic optical fiber 110 shown in FIG. 1 facing each other to a light source and a camera located at the rear of the smartphone. In this case, the light emitting unit 130, the light receiving unit 140, and measurement The unit 150 may be replaced with an LED light source, a camera, and a built-in signal processor provided on the front of the smartphone, respectively. The signal processing unit may be implemented as a separate application program or app.

In addition, the smartphone may output and provide whether or not mercury in the aqueous solution is detected and a mercury concentration value on the screen based on the light transmittance measured using the output light of the LED light source and the received light of the camera.

According to the present invention as described above, when a plastic optical fiber sensor in which a rhodamine derivative having high light-sensitive properties is inserted is implemented, and when light is irradiated at one end, mercury is removed in an aqueous solution environment based on the light transmittance observed at the other end. In addition to more effective detection, it provides the advantage of being able to quickly and accurately measure the mercury concentration.

The present invention has been described with reference to the embodiments shown in the drawings, but these are only exemplary, and those of ordinary skill in the art will appreciate that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical scope of the present invention should be determined by the technical spirit of the appended claims.

100: plastic optical fiber mercury sensor 110: plastic optical fiber
111: hole 120: rhodamine derivative
130: light emitting unit 140: light receiving unit
150: measuring unit 160: support

Claims (8)

A plastic optical fiber in which a hole communicating with the outside is formed at a central portion in the longitudinal direction, and light of a set wavelength band is incident on one end while the hole portion is immersed in an aqueous solution to be measured;
A rhodamine derivative inserted into the hole of the plastic optical fiber so as to be positioned on the optical path; And
It is formed of a transparent material including Teflon or silicon, and includes a support for fixing the rhodamine derivative inside the hole while supporting the rhodamine derivative,
Mercury in the aqueous solution is sensed based on the light transmittance observed from light output to the other end through the rhodamine derivative after incident on one end of the plastic optical fiber,
The hole is formed in a long shape parallel to the longitudinal direction of the plastic optical fiber,
The support,
A rhodamine-based plastic optical fiber mercury sensor that is inserted so as to be biased in an edge region located in a direction from which light exits among both edges of the hole, and the aqueous solution is filled in the remaining empty space of the hole during the immersion. The method according to claim 1,
Rhodamine-based plastic optical fiber mercury sensor in which the higher the mercury concentration in the aqueous solution, the more light the rhodamine derivative absorbs and the light transmittance is observed to be a lower value. The method according to claim 1,
The set wavelength band is a rhodamine-based plastic optical fiber mercury sensor having a range of 520 to 540 nm. The method according to claim 1,
A light-emitting unit for incident light of the set wavelength band to one end of the plastic optical fiber; And
A light receiving unit configured to receive light output to the other end of the plastic optical fiber; And
Rhodamine-based plastic optical fiber mercury sensor further comprising a measuring unit that measures light transmittance from the received light and provides a corresponding concentration value and whether mercury is detected based on the light transmittance. The method of claim 4,
The light emitting part, the light receiving part, and the measuring part,
It corresponds to the LED light source, camera and signal processing unit provided in the user terminal,
The user terminal,
A rhodamine-based plastic optical fiber mercury sensor that outputs whether the mercury is detected and the concentration value on the screen. delete delete The method according to claim 1,
A rhodamine-based plastic optical fiber mercury sensor formed in a plurality of holes at predetermined intervals along the length direction of the plastic optical fiber.

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