KR102349009B1 - Formaldehyde detection sensor comprising core-shell polymer materials and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a formaldehyde detection sensor including a core-shell polymer material and a method for manufacturing the same. Particularly, the present invention relates to polystyrene-polyaniline (PS-PANI) particles having a core-shell structure for use in a formaldehyde sensor, a method for preparing the same, a formaldehyde detection sensor including the PS-PANI particles having a core-shell structure, and a method for manufacturing the sensor. The formaldehyde detection sensor according to the present invention sensitively responds to formaldehyde to detect formaldehyde in a short time and can be reused to provide high cost-efficiency.

Description

Formaldehyde detection sensor comprising core-shell polymer materials and method for manufacturing the same

The present invention relates to a formaldehyde detection sensor including a polymer material having a core-shell structure and a method for manufacturing the same. More specifically, the present invention relates to polystyrene-polyaniline (PS-PANI) particles having a core-shell structure for a formaldehyde detection sensor, a manufacturing method thereof, a formaldehyde detection sensor comprising polystyrene-polyaniline having a core-shell structure, and the sensor It relates to a manufacturing method of The formaldehyde detection sensor according to the present invention can not only detect formaldehyde in a short time by sensitively reacting to formaldehyde, but also can be reused, so it can be usefully used from an economical point of view.

Among the research reports and commercialized products for detecting formaldehyde, a sensor using metal oxide as a sensing material or an analysis device such as gas chromatography or high-performance liquid chromatography is used, but the operating temperature is high, high cost, high energy consumption, and It has disadvantages such as low portability. On the other hand, when a polymer material including a conductive polymer is applied as a sensing material, it can be synthesized relatively easily, can easily control electrical properties, and can be manufactured at low cost, low energy consumption, and flexible sensor can be manufactured. .

Among the studies on formaldehyde sensors applied with metals and inorganic materials, recently published research reports [①Physica E: Low-dimensional Systems and Nanostructures, Vol.118, 113953(2020), ②Sensors and Actuators B: Chemical, Vol. 308, 127689(2020), ③Sensors and Actuators B: Chemical, Vol.283, 714-723(2019)] 3 cases are noteworthy. In these research reports, it was reported that the response and recovery time for the formaldehyde sensor performance was less than a few seconds, and the detection concentration was about 0.5-5 ppm. However, since the operating temperature of the sensor to detect formaldehyde requires a high temperature of about 40 to 360 ℃, and it is expected that the sensor will need a preparation time to reach the operating temperature, it is judged that it is impossible to detect formaldehyde in real time. do.

Physica E: Low-dimensional Systems and Nanostructures, Vol.118, 113953 (2020) Sensors and Actuators B: Chemical, Vol.308, 127689 (2020) Sensors and Actuators B: Chemical, Vol.283, 714-723 (2019)

As a result of the present inventors' diligent efforts to manufacture a formaldehyde detection sensor with excellent detection sensitivity of formaldehyde, polystyrene (PS) is located in the core, and polyaniline (PANI) coating layer is formed on the outer peripheral surface of the core. When a formaldehyde detection sensor is manufactured using polyaniline (PS-PANI) particles, excellent sensitivity is shown even when the formaldehyde concentration is 10 ppm or even 1 ppm, and as a result of reversibility evaluation, all formaldehyde detection sensors are By detecting the aldehyde, it was confirmed that reuse is possible, and the present invention was completed.

An object of the present invention is to provide polystyrene-polyaniline (PS-PANI) particles having a core-shell structure for a formaldehyde detection sensor.

Another object of the present invention is to provide a method for producing polystyrene-polyaniline (PS-PANI) particles having a core-shell structure for a formaldehyde detection sensor.

Another object of the present invention is to provide a formaldehyde detection sensor including polystyrene-polyaniline (PS-PANI) particles having the core-shell structure.

Another object of the present invention is to provide a method for manufacturing a formaldehyde detection sensor including the polystyrene-polyaniline (PS-PANI) particles having the core-shell structure.

In order to achieve the above object,

Polystyrene-polyaniline (PS-PANI) particles of a core-shell structure for a formaldehyde detection sensor in which polystyrene (PS) is located in the core, and a polyaniline (PANI) coating layer is formed on the outer peripheral surface of the core to provide.

In addition, the present invention comprises the steps of (A) preparing a polystyrene (PS) core from styrene as a raw material by a dispersion polymerization process; And (B) swelling-diffusion-interfacial polymerization (Swelling-Diffusion-Interfacial Polymerization, SDIPM) process by coating the polystyrene core with polyaniline (PANI) to produce polystyrene-polyaniline (PS-PANI) particles of a core-shell structure It provides a method for producing polystyrene-polyaniline (PS-PANI) particles of a core-shell structure for a formaldehyde detection sensor, comprising the step of:

In addition, the present invention is an insulating layer substrate; electrode; and polystyrene-polyaniline (PS-PANI) particles of a core-shell structure in which polystyrene (PS) is located in the core, and a polyaniline (PANI) coating layer is formed on the outer peripheral surface (shell) of the central part, stacked in this order A formaldehyde detection sensor is provided.

In addition, the present invention comprises the steps of (A) manufacturing an IDE sensor device in which an IDE pattern is formed on a substrate; (B) preparing polystyrene-polyaniline (PS-PANI) particles having a core-shell structure as a sensing material; (C) preparing a coating solution by dissolving the polystyrene-polyaniline particles prepared in (B) in tetrahydrofuran; and (D) coating the coating solution of (C) on the IDE sensor device prepared in step (A).

The formaldehyde detection sensor according to the present invention reacts sensitively to formaldehyde to detect formaldehyde within a short time, and is expected to be useful in economic terms because it can be reused.

1 shows scanning electron micrographs of (a) PS particles, and (b) and (c) PS-PANI (3:1) core-shell particles.
2 shows transmission electron micrographs of (a) PS-PANI (3:1) core-shell particles and (b) Hollow PANI particles.
3 shows a film prepared using PS-PANI core-shell particles.
4 shows a method of manufacturing an IDE device applied formaldehyde sensor and an operating principle of the sensor.
Figure 5 shows the sensitivity of the sensor to 10 ppm formaldehyde of PS-PANI (3:1) core-shell particles.
Figure 6 shows the sensitivity of the sensor according to the change in the concentration of formaldehyde 1, 5, 10 and 50 ppm of PS-PANI (3:1) core-shell particles.
7 shows the sensor sensing reversibility at 10 ppm formaldehyde of PS-PANI (3:1) core-shell particles.

The present invention provides polystyrene-polyaniline (PS-PANI) particles having a core-shell structure, a method for preparing the same, and a formaldehyde detection sensor using the same.

According to the first embodiment,

Polystyrene-polyaniline (PS-PANI) particles of a core-shell structure for a formaldehyde detection sensor in which polystyrene (PS) is located in the core, and a polyaniline (PANI) coating layer is formed on the outer peripheral surface of the core would like to provide

In the polystyrene-polyaniline particles according to the present invention, the weight ratio of the polystyrene and polyaniline is 4:1 to 2:1, preferably 3:1.

According to the second embodiment,

the present invention

(A) preparing a polystyrene (PS) core from styrene as a raw material by a dispersion polymerization process; and

(B) Swelling-Diffusion-Interfacial Polymerization (SDIPM) process by coating the polystyrene core with polyaniline (PANI) to produce polystyrene-polyaniline (PS-PANI) particles of a core-shell structure It provides a method for producing polystyrene-polyaniline (PS-PANI) particles having a core-shell structure for a formaldehyde detection sensor, comprising the steps of:

In the method for producing polystyrene-polyaniline particles according to the present invention, the weight ratio of the polystyrene and polyaniline is 4:1 to 2:1, preferably 3:1.

In the method for producing polystyrene-polyaniline particles according to the present invention, the step (A) is a solution containing polyvinylpyrrolidone (PVP) as a stabilizer, azobisisobutyronitile (AIBN) as an initiator and styrene as a precursor at 60 to 80 degrees. It may include the step of carrying out the polymerization reaction by stirring for 12 to 24 hours.

In the method for producing polystyrene-polyaniline particles according to the present invention, the step (B) includes (b-1) adding aniline to a solution containing polystyrene and then stirring to swell the polystyrene particles; and (b-2) adding an oxidizing agent and a dopant to the solution of step (b-1), followed by stirring at room temperature for 12 to 24 hours to perform a polymerization reaction. Here, the oxidizing agent may be selected from potassium peroxo disulfate (KPS), ammonium persulfate (APS) or sodium persulfate (SPS). The doping agent is hydrofluoric acid (HF), hydrochloric acid (HCl), perchloric acid (HClO ₄ ), nitric acid (HNO ₃ ), sulfuric acid (H ₂ SO ₄ ), fluorosulfonic acid (FSO ₃ H), sulfonic acid (CH ₃ SO ₃ H) , camphorsulfonic acid, polystyrenesulfonate (PSS), p-toluenesulfonic acid (p-TSA, p-toluenesulfonic acid), or dodecyl benzene sulfonic acid (DBSA, dodecyl benzene sulfonic acid).

According to the third embodiment,

The present invention is an insulating layer substrate; electrode; and polystyrene-polyaniline (PS-PANI) particles of a core-shell structure in which polystyrene (PS) is located in the core, and a polyaniline (PANI) coating layer is formed on the outer peripheral surface (shell) of the central part, stacked in this order It is intended to provide a formaldehyde detection sensor.

In the formaldehyde detection sensor according to the present invention, the weight ratio of the polystyrene and polyaniline is 4:1 to 2:1, preferably 3:1.

In the formaldehyde detection sensor according to the present invention, the substrate is selected from a semiconductor substrate, a conductive substrate, a non-conductive substrate, and a silicon on insulator (SOI). For example, the semiconductor substrate may be a silicon substrate or a III-V semiconductor substrate, and the conductive substrate may be a metal substrate or a conductive organic compound substrate, and the non-conductive substrate may be a glass substrate, a polymer compound substrate, or the like. can be used

In the formaldehyde detection sensor according to the present invention, the insulating layer is silicon dioxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), tantalum oxide (Ta ₂ O ₅ ), zirconium oxide (ZrO ₂ ), hafnium dioxide (HfO ₂ ), titanium dioxide (TiO ₂ ), silicon oxynitride (SiON), silicon nitride (Si ₃ N ₄ ), hafnium silicon oxynitride (HfSiON), or hafnium silicate (HfSi _X O _Y , where 0.1<X<9 and 2<Y<4).

In the formaldehyde detection sensor according to the present invention, the electrode includes a first electrode and a second electrode, and is characterized in that it is made of the same or different metal materials. The electrode material is gold (Au), nickel (Ni), platinum (Pt), palladium (Pd), iridium (Ir), silver (Ag), rhodium (Rh), ruthenium (Ru), stainless steel, aluminum ( Al), molybdenum (Mo), chromium (Cr), copper (Cu), tungsten (W), and combinations thereof, and the shape of the electrode is rectangular, oval, circular, polygonal, or a combination thereof. can be selected from

In the formaldehyde detection sensor according to the present invention, the sensor is characterized in that it can be reused 1 to 10 times.

According to the fourth embodiment,

the present invention

(A) manufacturing an IDE sensor device in which an IDE pattern is formed on a substrate;

(B) preparing polystyrene-polyaniline (PS-PANI) particles having a core-shell structure as a sensing material;

(C) preparing a coating solution by dissolving the polystyrene-polyaniline particles prepared in (B) in tetrahydrofuran; and

(D) coating the coating solution of (C) on the IDE sensor device prepared in step (A); to provide a method of manufacturing a formaldehyde detection sensor comprising a.

In the method for manufacturing a formaldehyde detection sensor according to the present invention, the step (A) comprises:

(a-1) applying a pressure to ^{10 -6} to 10 ^-7 (Torr) in a chamber by placing a metallic shadow mask on the substrate;

(a-2) depositing a pattern using gold as a deposition material, and then removing the metal shadow mask after cooling to form an IDE pattern on the substrate; and

(a-3) vacuum annealing the substrate on which the IDE pattern is formed, and manufacturing an IDE sensor device. Here, the deposition may be selected from an electron beam deposition method, a sputter deposition method, a pulsed laser deposition method, or an inclined angle deposition method.

In the method for manufacturing a formaldehyde detection sensor according to the present invention, the weight ratio of polystyrene and polyaniline in step (B) is 4:1 to 2:1, preferably 3:1.

In the method for manufacturing a formaldehyde detection sensor according to the present invention, the step (B) comprises:

(b-1) preparing a polystyrene (PS) core using styrene as a raw material by a dispersion polymerization process; and

(b-2) Polystyrene-polyaniline (PS-PANI) particles of a core-shell structure by coating the polystyrene core with polyaniline (PANI) by a swelling-diffusion-interfacial polymerization (SDIPM) process It characterized in that it comprises the step of generating.

In the method for manufacturing a formaldehyde detection sensor according to the present invention, the polystyrene-polyaniline particles in the coating solution in step (C) are included in an amount of 10 to 20 wt% based on the tetrahydrofuran content. When the content of polystyrene-polyaniline particles is 20 wt% or more, they are not well soluble in solvents, which may cause difficulties in uniform coating when coating the IDE sensor device. It may degrade the performance of the detection sensor.

In the method for manufacturing a formaldehyde detection sensor according to the present invention, the coating in step (D) is characterized in that 500 to 200 μl of the coating solution is applied. When the amount of the coating solution is less than 50 μl, it is not possible to completely coat the entire IDE pattern, and a non-uniform coating film is formed. When a coating film is formed on only a portion of the IDE pattern, not the entirety of the IDE pattern, the detection area of the formaldehyde detection sensor is reduced as well as the coating film is non-uniform, so that the performance of the formaldehyde detection sensor is deteriorated. In addition, when the amount of the coating solution exceeds 200 μl, the thickness of the coating film coated on the IDE sensor device increases accordingly. As the thickness of the coating film increases as described above, the time required for swelling to occur increases because the time for formaldehyde to penetrate and absorb into the polystyrene-polyaniline coating film increases when formaldehyde comes into contact. It causes the problem of lowering the sensitivity. In addition, since the efficiency of detecting formaldehyde compared to the amount required as a sensing material is not high, it is not suitable from an economic point of view.

Hereinafter, the present invention will be described in more detail through examples. However, these are only for describing the present invention in more detail, and the scope of the present invention is not limited thereto.

<Example>

Example 1. Preparation of PS-PANI core-shell particles for a sensor for detection of formaldehyde

1-1. Preparation of PS Core Particles

4 g of polyvinylpyrrolidone (PVP) was placed in 170 mL of isopropyl alcohol, mixed and stirred, and the resulting transparent solution was transferred to a reaction tank installed in a water bath temperature controlled at 65 °C. 22 mL of monomer Styrene was added to a reaction tank containing a mixed solution of PVP and isopropyl alcohol using a pipette and stirred for about 10 minutes. A solution obtained by dissolving 0.2 g of a reaction initiator AIBN (Azobisisobutyronitrile) in 50 mL of isopropyl alcohol was slowly added to the reactor using a pipette. After adding the AIBN solution, the polymerization reaction was carried out at 65 ° C. for 12 hours, and the reaction product was washed with isopropyl alcohol and ethanol twice each by centrifugation (10500 rpm, 10 minutes) and redispersion. Finally, solid content was obtained by centrifugation (10500 rpm, 10 minutes) using ethanol, and PS particles were prepared after drying at room temperature for 12 hours.

1-2. PS-PANI core-shell particle production by applying PS core particle

Aniline 0.4 g was added to 60 mL of DI-water and sonicated in an ice bath for 30 minutes. After that, 1.2 g of PS powder was added to the aniline solution and further sonicated in an ice bath for 30 minutes. After stirring the suspension containing Aniline and PS in an ice bath for 5 hours, transfer to a round flask, and use a syringe to prepare a solution prepared by dissolving 0.980 g of Ammonium persulfate (APS), an oxidizing agent, in 5 mL of DI-water using a syringe. Slowly added to the round flask containing the suspension. When the white suspension changed to a yellow suspension, 4.3 mL of 1 M hydrochloric acid as a dopant was slowly added dropwise into the round flask containing the reaction mixture. After that, polymerization was carried out while stirring in an ice bath for 5 hours and at room temperature for 18 hours, followed by centrifugation (12000 rpm, 15 minutes) and redispersion a total of 4 times using DI-water, followed by washing with DI water. -Water was used to obtain a solid content by centrifugation (12000 rpm, 15 minutes), and after drying at room temperature for 12 hours, dark green PS-PANI core-shell particles were prepared.

The results of scanning electron microscope (SEM) analysis of the PS particles and PS-PANI (3:1) core-shell particles prepared in this Example are shown in FIG. 1 , and PS-PANI (3:1) The transmission electron microscope (TEM) analysis result of the core-shell particles is shown in FIG. 2(a), and the core-shell structure of the PS-PANI (3:1) particles prepared in this example The transmission electron micrograph of the hollow PANI particles obtained after the PS core was removed using the organic solvent Tetrahydrofuran (THF) to confirm this is shown in FIG. 2(b).

Example 2. Film production using PS-PANI core-shell particles

In order to prepare a large-area film using the PS-PANI core-shell particles prepared in Example 1, a Tetrahyderofuran (THF) solution in which the PS-PANI core-shell particles were dissolved was prepared, and the prepared solution was mixed with polyester. (Polyester) The film was uniformly coated through a bar coating method (RDS bar coater (No. 5), moisture film thickness 11.43 μm). Polyester films coated with PS-PANI solution were prepared in various sizes and are shown in FIGS. 3a-b. The thickness of the film was prepared to be 10 μm or less, and when the film was bent at various angles, it was confirmed that no cracks occurred on the surface of the film ( FIGS. 3c-e ).

Example 3. Fabrication of IDE device application formaldehyde sensor

An electron beam evaporation process was used to manufacture the IDE, which is the basic element of the formaldehyde detection sensor according to the present invention. A metallic shadow mask made of stainless steel manufactured in an IDE pattern was placed on the substrate, then placed in a chamber and maintained in a high vacuum state of about 7.5×10 −5 Torr. An electron beam generated by an electron gun sublimated gold as a source material to a vapor state, and the generated gold vapor was deposited on a substrate according to a shadow mask pattern to form an IDE pattern. A 15 wt% Tetrahydrofuran (THF) solution in which the PS-PANI core-shell particles prepared in Example 1 were dissolved was prepared, and 100 μL of the solution was coated on the IDE device by the doctor blade coating method to prepare a formaldehyde sensor ( Fig. 4).

Example 4. Sensitivity analysis at specific formaldehyde concentration of formaldehyde detection sensor using PS-PANI core-shell particles and IDE sensor element

After connecting an electrometer to the IDE device applied formaldehyde sensor prepared in Example 3, an aqueous solution of formaldehyde (37wt%) was adjusted to a concentration of 10 ppm and injected using a micro syringe to measure the resistance change. Sensitivity to formaldehyde was analyzed by converting the measured resistance value into a relative resistance value (%) using the following relation (1).

(In the above relation (1), R _N is a resistance value measured under a nitrogen atmosphere, and R _F is a resistance value measured after formaldehyde is injected.)

As a result, when exposed to formaldehyde, the relative resistance value (%) decreased almost vertically and reached the maximum value of -18.7% within about 3 minutes. A tendency to recover by injection was confirmed (FIG. 5). That is, it was confirmed that the PS-PANI (3:1) core-shell particles had high sensitivity to 10 ppm of formaldehyde, and it took about 30 minutes until the relative resistance value was restored to 0 by injecting nitrogen.

Example 5. Sensitivity change analysis according to formaldehyde concentration of formaldehyde detection sensor to which PS-PANI core-shell particles and IDE sensor element are applied

After connecting the electrometer to the IDE device applied formaldehyde sensor prepared in Example 3, the formaldehyde aqueous solution (37wt%) was adjusted to a concentration of 1, 5, 10 ppm, etc., and the resistance change caused by injecting it using a micro syringe measured. The measurement test method for detecting formaldehyde was performed in the same manner as in Example 4, and the sensitivity was compared by measuring while changing the formaldehyde concentration using the same PS-PANI (3:1) core-shell particles as in Example 4. . The formaldehyde concentration was changed to 1 ppm, 5 ppm, and 10 ppm, and the sensitivity was analyzed by measuring the resistance change and converting it into a relative resistance value (%) through the relation (1) of Example 4 above.

As a result, the relative resistance value when the formaldehyde concentration is 1 ppm when the relative resistance value at the response time 40 minutes is compared with the response time of 40 minutes after reaching the maximum relative resistance value as the time to reach the maximum equilibrium. When silver is about -9.9%, at 5 ppm, the relative resistance value is about -15%, at 10 ppm, the relative resistance value is about -18.7%, and at 50 ppm, the relative resistance value is about -37.6%, increasing the formaldehyde concentration. As a result, the maximum relative resistance increased. In addition, it was confirmed that the maximum relative resistance value was reached within about 5 minutes at all formaldehyde concentrations, and through the quantitative change in the relative resistance value according to the formaldehyde concentration, the formaldehyde concentration was It was confirmed that it is an important factor to control the sensing performance of the used formaldehyde sensor. In addition, PS-PANI (3:1) core-shell particles showed excellent sensitivity to formaldehyde of at least 1 ppm in this experiment, and exhibited the lowest minimum detection concentration among polyaniline-applied formaldehyde sensors (FIG. 6).

Example 6. Reversibility evaluation of formaldehyde detection sensor using PS-PANI core-shell particles and IDE sensor element

Resistance of the same PS-PANI (3:1) core-shell particles as in Examples 4 and 5 was measured twice under the same conditions for 10 ppm formaldehyde, and after the first measurement, a separate drying process or No treatment was performed. The measurement result was converted into a relative resistance value (%) using the relational expression (1) of Example 4, and then the reversibility of the formaldehyde detection sensor was evaluated.

As a result, when the measurement was repeated three times under the same conditions and the same method as in Example 4, the maximum relative resistance value in the first measurement was -18.7%, the maximum relative resistance value in the second measurement was -17.3%, and the maximum relative resistance value in the third measurement The resistance value was -15.6%, and it was confirmed that the maximum relative resistance value was maintained relatively high, and excellent reversibility was confirmed. In addition, the recovery time was constant for about 30 minutes, and all of them showed a phenomenon in which the relative resistance value returned to 0, that is, to the initial resistance value (FIG. 7). This reversibility is a sensor performance that has not been presented in conventional polyaniline-based formaldehyde detection sensors.

As described above in detail a specific part of the content of the present invention, for those of ordinary skill in the art, it is clear that this specific description is only a preferred embodiment, and the scope of the present invention is not limited thereby. something to do. Accordingly, it is intended that the substantial scope of the present invention be defined by the appended claims and their equivalents.

Claims (10)

delete delete delete delete (A) manufacturing an IDE sensor device in which an IDE pattern is formed on a substrate;
(B) preparing polystyrene-polyaniline (PS-PANI) particles having a core-shell structure as a sensing material;
(C) preparing a coating solution by dissolving the polystyrene-polyaniline particles prepared in (B) in tetrahydrofuran; and
(D) coating the coating solution of (C) on the IDE sensor device prepared in step (A); manufacturing method of a formaldehyde detection sensor comprising a.
6. The method of claim 5,
The step (A) is:
(a-1) applying a pressure to ^{10 -6} to 10 ^-7 (Torr) in a chamber by placing a metallic shadow mask on the substrate;
(a-2) forming an IDE pattern on a substrate by depositing a pattern using gold as a deposition material, cooling it, and then removing the metal shadow mask; and
(a-3) vacuum heat treatment of the substrate on which the IDE pattern is formed, characterized in that it comprises the step of manufacturing an IDE sensor device.
6. The method of claim 5,
In the step (B), the weight ratio of polystyrene and polyaniline is 4:1 to 2:1, characterized in that the method.
6. The method of claim 5,
The step (B) is:
(b-1) preparing a polystyrene (PS) core using styrene as a raw material by a dispersion polymerization process; and
(b-2) Polystyrene-polyaniline (PS-PANI) particles of a core-shell structure by coating the polystyrene core with polyaniline (PANI) by a swelling-diffusion-interfacial polymerization (SDIPM) process A method, characterized in that it comprises the step of generating.
6. The method of claim 5,
The method, characterized in that the polystyrene-polyaniline particles in the coating solution in step (C) are included in an amount of 10 to 20 wt% based on the tetrahydrofuran content.
6. The method of claim 5,
The coating in step (D) is characterized in that 50 to 200 μl of the coating solution is applied, the method.

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