Preparation method of flexible color developing film or array device based on dye and doped metal oxide nanoparticles and application of flexible color developing film or array device in oxygen / ammonia gas detection

Abstract

The invention discloses a preparation method of a flexible color developing film or an array device based on dye and doped metal oxide nanoparticles and application of the flexible color developing film or the array device in oxygen / ammonia gas detection, and belongs to the field of ammonia gas and oxygen gas detection. The preparation method comprises the following steps: S1, respectively preparing a precursor solution containing Cu or Fe-doped metal oxide nanocrystals and a polymer solution; s2, mixing the two solutions prepared in S1, adding rhodamine derivative dye powder, and uniformly stirring and mixing to obtain a mixed solution of dye / metal oxide precursor / polymer; s3-A, carrying out spin coating or blade coating on the mixed solution on the surface of glass to form a film, and then drying to obtain a thin film; or S3-B, dripping the mixed solution into the arrayed grid pattern on the surface of the glass, and drying to obtain the arrayed device. The device has the advantages of low cost and easiness in manufacturing, can be simultaneously applied to the field of oxygen and ammonia gas detection, and can be repeatedly used.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of a flexible color-developing film or array device based on dye and doped metal oxide nanoparticles and application in oxygen / ammonia detection, and belongs to the ammonia and oxygen detection field. BACKGROUND

[0002] In many fields such as environmental detection, chemical industry, medical diagnosis and food health, ammonia is discharged in large quantities. For example, ammonia is part of the nitrogen cycle, and bacteria in the soil produce ammonia when decomposing organic matter. It is very dangerous for the human body to be exposed to an ammonia environment for a long time. Studies have shown that at a low concentration of 50 ppm, it will irritate the eyes, skin and other parts of the human body, and at 200 ppm, it will severely irritate the nasal cavity and throat. According to the Chinese 'GT18883-2022 Indoor Air Quality Standard', the average ammonia concentration in the room should be less than 0.25 ppm for 1 hour, so it is crucial to detect the ammonia level.

[0003] Oxygen is also crucial to life. A normal human body only needs a certain concentration of oxygen, and too high or too low a concentration of oxygen is harmful to humans. Too low a partial pressure of oxygen will cause hypoxia, and too high a partial pressure of oxygen will cause oxygen poisoning. As a colorless and odorless gas, oxygen exceeding a certain limit value mixed with flammable gas can easily cause an explosion, and oxygen can also cause oxidation in industrial manufacturing processes, reducing product quality. Therefore, the detection of oxygen concentration plays an important role in daily life, environmental monitoring, health and hygiene, industrial exploration and the like.

[0004] Based on the above needs, various gas sensors have developed rapidly, among which optical colorimetric gas sensors do not require complex conduction components. The material can realize gas detection by light emission / fluorescence quenching or color change under the action of gas. The sensing element in the colorimetric sensor is usually made of chemical dye. Such dye is generally an organic substance, which is prone to aging and decomposition under ultraviolet irradiation and humidity. Therefore, the response of the sensor will change over time. On the other hand, the sol-gel method usually requires fine experimental conditions, which is not conducive to large-scale and low-cost preparation. Therefore, it is necessary to develop a new type of ammonia / oxygen flexible sensing film based on dye to solve the above problems. SUMMARY

[0005] The present application quickly prepares a low-cost color-changeable flexible film by using organic dye based on rhodamine derivative, inorganic nanoparticles doped with metal ions and polymer materials, and realizes recyclable dual detection of ammonia and oxygen.

[0006] According to a first aspect of the present application, a preparation method of a flexible color-developing film or array device based on dye and doped metal oxide nanoparticles is provided. In combination with in-situ growth of metal oxide particles in the polymer film, organic dye molecules can also be encapsulated in the film by the polymer, reducing the decomposition of the dye under light and humidity.

[0007] A preparation method of a flexible color-developing film or array device based on dye and doped metal oxide nanoparticles, the preparation method comprising: S1, respectively, preparing a metal oxide nanocrystal precursor solution containing Cu or Fe doped metal oxide, a polymer solution; S2, mixing the two solutions prepared in S1, adding rhodamine derivative dye powder, stirring to mix uniformly, to obtain a mixed solution of dye / metal oxide precursor / polymer; S3-A, spin coating or blade coating the mixed solution on a glass surface to form a film, and then drying to obtain a thin film; or S3-B, dropping the mixed solution into an arrayed grid pattern on the glass surface, and drying to obtain an array device.

[0008] Optionally, in step S1, the metal oxide is zinc oxide.

[0009] Optionally, in step S1, the preparation method of the metal oxide nanocrystal precursor solution containing Cu or Fe doped metal oxide comprises: adding hydrogen peroxide to ZnCl2, dissolving in N,N-dimethylformamide, adding CuCl or FeCl2, and stirring uniformly.

[0010] Optionally, the mass ratio of CuCl or FeCl2 to ZnCl2 is 0.01-0.1:1.

[0011] Optionally, the concentration of the hydrogen peroxide is 30%.

[0012] Optionally, the amount of ZnCl2, 30% hydrogen peroxide, N,N-dimethylformamide, CuCl or FeCl2 is 100-300 mg: 20-60 L: 500-1500 μL: 10-30 mg.

[0013] Optionally, the stirring is magnetic stirring, the stirring speed is 300 rpm, the stirring time is 1 h, and the room temperature is 25°C.

[0014] Optionally, the solution after stirring uniformly is sealed and stored.

[0015] Optionally, in step S1, the polymer of the polymer solution in step S1 is selected from at least one of PMMA and PVB. The concentration of the polymer solution is 0.1 g / L to 0.16 g / L.

[0016] Optionally, in step S1, the polymer powder is dissolved in dichloromethane to obtain the polymer solution.

[0017] Optionally, the amount of PMMA and dichloromethane is 2-4 g: 25-50 ml.

[0018] Optionally, in step S2, the mass ratio of CuCl or FeCl2 to the rhodamine derivative dye powder is 1:10-1:15.

[0019] Optionally, in step S2, the rhodamine derivative dye is at least one selected from 2-anilino-3-methyl-6-dibutylaminofluorane, 2'-(dibenzylamino)-6'-(diethylamino)fluorane, 1,3-dimethyl-6-diethylaminofluorane, 9-(ethyl(isopentyl)amino)-3'H-spiro[benzo[A]xanthene-12,1'-isobenzofuran]-3'-ketone, 6'-(diethylamino)-2'-(anilino)-3H-spiro[isobenzofuran-1,9'-xanthene]-3-ketone.

[0020] The prepared thin film can be removed from the glass after preparation, the whole thin film is flexible, and the thickness can be controlled in the range of about 500 nm to 10 mm, so the application range is wider, and the thin film can be attached to surfaces of various shapes.

[0021] In this application, during the preparation of the thin film by spin coating or blade coating, the operation parameters can be adjusted according to the actual need of the thickness.

[0022] As a preferred embodiment, the preparation method comprises the following steps: Preparation of metal oxide precursor solution: adding hydrogen peroxide to anhydrous ZnCl2, dissolving it in N,N-dimethylformamide to obtain a ZnCl2 solution, after the reaction solution is cooled to room temperature, adding CuCl or FeCl2, stirring uniformly, then stopping stirring, and storing in an oxygen-free environment.

[0023] Preparation of polymer solution: dissolving PMMA powder in dichloromethane, stirring after ultrasonic treatment until the PMMA is completely dissolved to obtain a PMMA polymer solution.

[0024] Mixing of dye, precursor solution and polymer solution: adding the ZnCl2 solution mixed with CuCl or FeCl2 to the PMMA polymer solution, then adding rhodamine derivative dye powder, stirring until the dye is uniformly dispersed in the solution to obtain a mixed solution of dye / metal oxide precursor / polymer.

[0025] Preparation of flexible gas sensitive thin film: clean sodium-calcium glass with water, isopropyl alcohol, acetone and ethanol, and plasma treat the surface of the glass. Spin-coat, blade-coat or drop-coat the mixed solution of dye / metal oxide precursor / polymer on the glass, spin-coat is to spin the mixed solution on the surface of the glass into a film using a spin coater, blade-coat is to drop the mixed solution on the glass and spread the liquid evenly on the glass using a blade, and drop-coat is to paste a frame around the glass using adhesive tape, and then drop the liquid in the frame to spread it evenly. Put the glass sample after spin-coating, blade-coating or drop-coating into a vacuum oven to dry into a film, and obtain a flexible gas sensitive thin film.

[0026] The present application relates to a preparation method of a flexible arrayed gas sensitive device based on dye and doped metal oxide nanoparticles, comprising the following steps: preparing a checkered pattern on the surface of clean sodium-calcium glass using adhesive tape, then dropping a mixed solution based on different color dyes and different dye concentrations in different areas of the checkered pattern, and putting it into a vacuum oven for drying treatment to obtain an arrayed gas sensitive device.

[0027] The dye includes but is not limited to various rhodamine derivatives, and the corresponding colors include but are not limited to pink, light red, green, black, etc. Rhodamine biological dye is a basic dye with xanthene as the parent body, and has a hydrazide spiro ring structure. When the dye is in a ring closed state, the dye itself is colorless. If the dye contacts with corresponding metal ions, the interaction between them can open the original spiro ring structure in the dye molecule, and the dye molecule and the metal ions further form a complex or a complex, which causes a color change visible to the naked eye. Rhodamine dye has good light stability, long wavelength emission, and is not sensitive to pH, etc.

[0028] According to a second aspect of the present application, the application of the flexible color developing thin film or arrayed device prepared by the above-mentioned preparation method in oxygen / ammonia detection is provided.

[0029] The application of the flexible color developing thin film or arrayed device prepared by the above-mentioned preparation method in oxygen / ammonia detection.

[0030] The beneficial effects that can be produced by the present application include: The preparation method of the flexible color developing thin film or arrayed device based on dye and doped metal oxide nanoparticles provided by the present application has the advantages of low cost and easy manufacturing, and in combination with the in-situ growth of metal oxide particles in the polymer thin film, the organic dye molecules can also be encapsulated in the thin film by the polymer, reducing the decomposition of the dye under light and humidity.

[0031] The prepared thin film can be peeled off from the glass after preparation, the whole thin film is flexible, the thickness can be controlled in the range of about 500 nm-10 mm, and thus the application range is wider, and the thin film can be attached to surfaces of various shapes.

[0032] The prepared flexible color-developing thin film or array device can be applied in oxygen and ammonia detection fields, and is reusable. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 Preparation process of the flexible gas-sensitive thin film based on dye and doped metal oxide nanoparticles; Figure 2 Transmission test method of the gas-sensitive thin film; Figure 3 Transmission spectrum of the thin film based on different color rhodamine derivative dyes; Figure 4 Mechanism of the flexible gas-sensitive thin film based on dye and doped metal oxide nanoparticles; Figure 5 Color change of the flexible gas-sensitive thin film prepared in Example 1 in the ammonia environment and reaction time, and reduction in the room temperature environment; Figure 6 Transmission spectrum corresponding to the color change of the flexible gas-sensitive thin film prepared in Example 1 in the ammonia environment; Figure 7 Color change of the flexible gas-sensitive thin film prepared in Example 2 in the oxygen environment and reaction time, and reduction in the vacuum UV environment. DETAILED DESCRIPTION

[0034] The present application will be described in detail below in combination with examples, but the present application is not limited to the examples.

[0035] Unless otherwise specified, the raw materials in the examples of the present application are purchased through commercial channels.

[0036] Unless otherwise specified, the test method is a conventional method, and the instrument setting is the recommended setting of the manufacturer.

[0037] The analysis method in the examples of the present application is as follows: The transmission test method of the gas-sensitive thin film is as follows: Figure 2As shown, the transmission spectrum analysis of the film uses an avatens spectrometer combined with a sealed air cavity (the optical fiber probe has been fixed in the air cavity) to test. During testing, the prepared film sample is first placed vertically in the air cavity, the film is attached to the glass, and is fixed vertically at the bottom of the air cavity. The air cavity is sealed, and the original air inside the air cavity is pumped out using a vacuum pump. The one end of the air outlet is closed, the other side of the air inlet is opened, and nitrogen, oxygen or ammonia is injected into the inside.

[0038] As shown, the transmission spectrum analysis of the film uses an avatens spectrometer combined with a sealed air cavity (the optical fiber probe has been fixed in the air cavity) to test. During testing, the prepared film sample is first placed vertically in the air cavity, the film is attached to the glass, and is fixed vertically at the bottom of the air cavity. The air cavity is sealed, and the original air inside the air cavity is pumped out using a vacuum pump. The one end of the air outlet is closed, the other side of the air inlet is opened, and nitrogen, oxygen or ammonia is injected into the inside. Figure 1 As shown, the transmission spectrum analysis of the film uses an avatens spectrometer combined with a sealed air cavity (the optical fiber probe has been fixed in the air cavity) to test. During testing, the prepared film sample is first placed vertically in the air cavity, the film is attached to the glass, and is fixed vertically at the bottom of the air cavity. The air cavity is sealed, and the original air inside the air cavity is pumped out using a vacuum pump. The one end of the air outlet is closed, the other side of the air inlet is opened, and nitrogen, oxygen or ammonia is injected into the inside.

[0039] Example 1 In 0.1 g of anhydrous ZnCl2, 20 ul of hydrogen peroxide (concentration 30%) is added, which is dissolved in 1.5 ml of N,N-dimethylformamide to obtain a ZnCl2 solution. After the reaction solution is cooled to room temperature, 0.015 g of CuCl is added, stirred for 2 h, and then stopped stirring, and placed in a glove box to isolate oxygen.

[0040] Preparation of polymer solution: 4 g of PMMA powder is dissolved in 50 ml of dichloromethane, and after ultrasonic treatment, stirring is carried out for 4 h until the PMMA is completely dissolved to obtain a PMMA polymer solution.

[0041] 100 ul of the mixed Cu-doped metal oxide nanocrystal precursor solution is added to 5 ml of the PMMA polymer solution, and then 0.08512 g of 1,3-dimethyl-6-diethylamino fluorofluorene dye powder is added, stirred for 2 h until the dye is uniformly dispersed in the solution, to obtain a mixed solution of dye / metal oxide precursor / polymer.

[0042] The mixed solution is spin-coated on the glass surface using a spin coater at a speed of 500 rpm for 20 s, and then the film sample is placed in a 40°C vacuum oven for 1 h to obtain a red film with a thickness of 760 nm.

[0043] As shown, the transmission spectrum analysis of the film uses an avatens spectrometer combined with a sealed air cavity (the optical fiber probe has been fixed in the air cavity) to test. During testing, the prepared film sample is first placed vertically in the air cavity, the film is attached to the glass, and is fixed vertically at the bottom of the air cavity. The air cavity is sealed, and the original air inside the air cavity is pumped out using a vacuum pump. The one end of the air outlet is closed, the other side of the air inlet is opened, and nitrogen, oxygen or ammonia is injected into the inside. Figure 5As shown, the film is placed in a sealed ammonia environment, and it can be found that the red color gradually fades, the film becomes transparent, and the discoloration time is 2-5 min. Then the transparent film is taken out of the ammonia environment, and it can be found that the film can gradually become red in the room temperature oxygen environment. The coloring time is 25 min.

[0044] The film is placed in a sealed oxygen-free environment, and a 365 nm light source is used to irradiate the film. It can be found that the color of the film changes from red to transparent. After the light source is turned off and oxygen is input until the oxygen content in the environment reaches 3-6%, it can be observed that the film changes from transparent to red.

[0045] As shown in Figure 6 , the prepared red film is tested for transmission spectrum from coloring to transparent to red in the ammonia environment by using a spectrometer combined with a sealed air cavity.

[0046] Example 2 0.1 g of anhydrous ZnCl2 is added with 20 ul of hydrogen peroxide, which is dissolved in 1.5 ml of N,N-dimethylformamide to obtain a ZnCl2 solution. After the reaction solution is cooled to room temperature, 0.015 g of CuCl is added, stirred for 2 h, and then stopped stirring. It is placed in a glove box to isolate oxygen and stored.

[0047] Preparation of polymer solution: 4 g of PMMA powder is dissolved in 50 ml of dichloromethane, and after ultrasonic treatment, stirring is performed for 4 h until the PMMA is completely dissolved to obtain a PMMA polymer solution.

[0048] 100 ul of mixed Cu-doped metal oxide nanocrystal precursor solution is added to 5 ml of PMMA polymer solution, and then 2-phenylamino-3-methyl-6-dibutylamino fluorophore powder is added. Stirring is performed for 2 h until the dye is uniformly dispersed in the solution to obtain a mixed solution of dye / metal oxide precursor / polymer.

[0049] The mixed solution is spin-coated onto a glass surface by using a spin coater at a speed of 500 rpm for 20 s. Then the film sample is placed in a 40 degree Celsius vacuum oven for drying for 1 h to obtain a black film with a thickness of 800 nm.

[0050] As shown in Figure 7 , the film is placed in a sealed oxygen-free environment, and a 365 nm light source is used to irradiate the film for 30 min. It can be found that the color of the film changes from black to transparent. After the light source is turned off and oxygen is input until the oxygen content in the environment reaches 3-6%, it can be observed that the film changes from transparent to black.

[0051] Example 3 Add 20 μL of hydrogen peroxide to 0.1 g of anhydrous ZnCl2 and dissolve it in 1.5 mL of N,N-dimethylformamide to obtain a ZnCl2 solution. After the reaction solution is cooled to room temperature, add 0.02 g of FeCl2 and stir for 2 h to mix evenly. Then stop stirring and store in a glove box to isolate it from oxygen.

[0052] Preparation of polymer solution: Dissolve 4g of PMMA powder in 50ml of dichloromethane, sonicate and stir for 4h until PMMA is completely dissolved to obtain PMMA polymer solution.

[0053] 100 μL of Fe-doped metal oxide nanocrystal precursor solution was added to 5 mL of PMMA polymer solution, followed by 0.112 g of 6'-(diethylamino)-2'-(phenylamino)-3H-spiro[isobenzofuran-1,9'-xanthan gum]-3-one dye powder. The mixture was stirred for 2 h until the dye was uniformly dispersed, resulting in a mixed solution of dye / metal oxide precursor / polymer.

[0054] Using a spin coater, the mixed solution was spin-coated onto the glass surface at a speed of 500 rpm for 20 seconds. The film sample was then dried in a vacuum oven at 40 degrees Celsius for 1 hour to obtain a green film with a thickness of 800 nm.

[0055] When the film is placed in a sealed ammonia environment, the green color gradually fades and the film becomes transparent, with a color change time of 10 minutes. Then, the transparent film is removed from the ammonia environment, and it is observed that the film gradually turns green in a room temperature aerobic environment, with a coloring time of 25 minutes.

[0056] like Figure 3 As shown, the molecular structure diagrams of different types of rhodamine derivative dyes and the transmission spectra of the corresponding prepared films are shown. The red dye corresponds to the red film prepared in Example 1, the black dye corresponds to the red film prepared in Example 2, and the green dye corresponds to the green film prepared in Example 1. It can be seen that different types of rhodamine dyes exhibit different colors such as red, green, and black, and can be further used to prepare arrayed color devices.

[0057] like Figure 4The diagram illustrates the mechanism of flexible gas-sensitive films based on dyes and doped metal oxide nanoparticles. It shows that when Cu or Fe is incorporated into zinc oxide, the dye forms complexes with the incorporated metal ions, resulting in different colors and thus coloring the film. When the film is in an NH3 environment, copper ions are reduced to cuprous ions, and the metal-dye complexes separate (using 2-phenylamino-3-methyl-6-dibutylaminofluorane as an example). The dye and cuprous ions coexist in the film, resulting in a transparent film. Alternatively, when the film is exposed to UV light in an oxygen-free environment, the nanoparticles absorb photons, generating electrons that transfer to Cu or Fe ions, converting them into cuprous or ferrous ions, causing the film to fade. In an oxygen-rich environment, the cuprous or ferrous ions in the transparent film are oxidized, converting to copper or iron ions, which can then combine with the dye to form complexes, resulting in the corresponding color of the film—the coloring process.

[0058] Example 4 A grid pattern was prepared on a clean 25mm x 25mm soda-lime glass surface using 50mm thick, 2mm wide 3M tape. The grid width was 2.5mm and the length was 2.5mm. Nine grid patterns were prepared on one piece of glass. Then, red, black, and green solutions prepared according to Examples 1, 2, and 3 were dropped onto different areas of the grid patterns, with a solution volume of 60ul. The solutions were then placed in a vacuum oven at 40°C for 1 hour to dry, thus preparing an arrayed gas-sensitive device.

[0059] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for fabricating flexible colorimetric thin films or arrayed devices based on dyes and doped metal oxide nanoparticles, characterized in that, The preparation method includes: S1 prepares metal oxide nanocrystal precursor solutions and polymer solutions containing doped Cu or Fe, respectively; S2: Mix the two solutions prepared in S1, add rhodamine derivative dye powder, stir and mix evenly to obtain a mixed solution of dye / metal oxide precursor / polymer. S3-A involves spin-coating or blade-coating the mixed solution onto a glass surface to form a film, followed by drying to obtain a thin film. or S3-B involves dropping a mixed solution onto an arrayed grid pattern on a glass surface, drying it, and obtaining an arrayed device.

2. The preparation method according to claim 1, characterized in that, In step S1, the metal oxide is zinc oxide.

3. The preparation method according to claim 1, characterized in that, Step S1, the method for preparing a metal oxide nanocrystal precursor solution containing Cu or Fe doped metal oxide nanocrystals, includes: Add hydrogen peroxide to ZnCl2, dissolve it in N,N-dimethylformamide, add CuCl or FeCl2, and stir until homogeneous to obtain the final product.

4. The preparation method according to claim 1, characterized in that, In step S1, the polymer in the polymer solution is selected from at least one of PMMA and PVB. The polymer concentration is 0.1 g / L to 0.16 g / L.

5. The preparation method according to claim 1, characterized in that, In step S1, the polymer powder is dissolved in dichloromethane to obtain a polymer solution.

6. The preparation method according to claim 3, characterized in that, In step S2, the mass ratio of CuCl or FeCl2 to Rhodamine derivative dye powder is 1:10-1:

15.

7. The preparation method according to claim 1, characterized in that, In step S2, the rhodamine derivative dye is selected from at least one of 2-phenylamino-3-methyl-6-dibutylaminofluorane, 2'-(dibenzylamino)-6'-(diethylamino)fluorane, 1,3-dimethyl-6-diethylaminofluorane, 9-(ethyl(isopentyl)amino)-3'H-spiro[benzo[A]oxanthracene-12,1'-isobenzofuran]-3'-one, and 6'-(diethylamino)-2'-(phenylamino)-3H-spiro[isobenzofuran-1,9'-xanthan gum]-3-one.

8. The application of the flexible colorimetric film or arrayed device prepared by the preparation method according to any one of claims 1 to 7 in oxygen / ammonia detection.

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