Method for improving performance of p-phenylenediamine squaric acid amide polymer nitrogen dioxide resistance-type sensor

Abstract

The invention relates to a method for improving the performance of a p-phenylenediamine squaric acid amide polymer nitrogen dioxide resistance-type sensor, and belongs to the technical field of organic semiconductor devices. The method comprises the following steps: sequentially carrying out ultrasonic cleaning on an interdigital electrode by adopting water, ethanol and acetone; the preparation method comprises the following steps: ultrasonically dispersing a certain amount of deuterated p-phenylenediamine squaric acid amide polymer in a solvent to obtain dispersion liquid; the mass ratio of the deuterated p-phenylenediamine squaric acid amide polymer to the solvent is 1: (400-600); the solvent is one or more of deuterated ethanol, deuterated chloroform and deuterated acetone; and brushing the dispersion liquid on an interdigital electrode, placing the interdigital electrode at room temperature, removing the solvent, and drying the interdigital electrode in a drying oven to obtain the deuterated p-phenylenediamine squaric acid amide polymer sensor for low-concentration nitrogen dioxide. The prepared device is short in response time, ppb-level nitrogen dioxide detection can be achieved, the detection limit is low, and the response is higher than that of common metal oxides.

Description

Technical Field

[0001] The invention relates to a method for improving the performance of a p-phenylenediamine-based squarylamide polymer nitrogen dioxide resistance sensor, belonging to the technical field of organic semiconductor devices. Background Art

[0002] Nitrogen oxides are one of the three major components of haze in the air, including nitrogen pentoxide and nitrogen dioxide (NO 2 ), nitric oxide, etc. Among them, the nitrogen oxide pollutants in the atmosphere mainly refer to NO and NO 2 , collectively referred to as NO x Its sources can be divided into natural sources and anthropogenic sources. Natural sources are mainly produced by nitrogen-fixing bacteria and lightning. Anthropogenic sources can be divided into fixed nitrogen oxide sources produced by fossil fuel combustion in enterprises and mobile sources of nitrogen oxides emitted by vehicles at low altitudes. Anthropogenic sources have the characteristics of high pollution intensity, wide pollution range, and concentrated emission area. 2 Will be with SO 2 The dust forms acid rain, causing the ozone layer to be depleted, and the NO contained in the ash formed by photochemical smog 2 Will also participate in PM 2.5 Different concentrations of NO can cause different degrees of harm to humans. As a colorless gas with a pungent odor, NO 2 Even at low concentrations it is harmful to the human body. 2 Inhalation can cause mild eye and upper respiratory tract irritation symptoms, such as throat discomfort and dry cough. When the concentration exceeds 1ppm, it will pose a threat to the human respiratory system. 2 In the environment, NO can cause respiratory diseases such as bronchitis, dyspnea, emphysema, and even heart disease. About two weeks after the pulmonary edema subsides, delayed obstructive bronchiolitis may occur. In addition, NO 2 It is also a major environmental pollutant that causes acid rain and photochemical smog, triggers surface water acidification, leads to eutrophication of water bodies (due to the richness of nutrients such as nitrogen and phosphorus in the water, the massive reproduction of algae leads to lack of oxygen), and increases the content of toxins in the water that are harmful to fish and other aquatic life.

[0003] Organic chemical resistors have attracted much attention due to their designable structure and low cost. High sensitivity, specific selectivity, reversible reaction / recovery and other robustness indicators are the key to evaluating sensory performance. However, in the design process of organic semiconductor sensing materials, improving their response / recovery ability often sacrifices high sensitivity. In view of the above problems, the present invention provides a method that can maintain high sensitivity while maintaining response / recovery ability. Summary of the invention

[0004] The invention provides a method for preparing a deuterated p-phenylenediamine-based squarylamide polymer and a method for preparing a nitrogen dioxide resistive sensor device based on the organic semiconductor material and application thereof.

[0005] The present invention discloses a method for preparing a deuterated p-phenylenediamine-based square acid amide polymer. The preparation method is as follows:

[0006] A certain amount of p-phenylenediamine-d4, diethyl squarate and reaction solvent A are added to a single-mouth pressure-resistant bottle equipped with a condensing device, and then the air in the reaction system is replaced with nitrogen. After replacement for 3-5 times, the reaction system is sealed, stirred and heated to the reaction temperature, and after a period of reaction, the stirring is stopped and the mixture is naturally cooled to room temperature, filtered, and vacuum dried to obtain a crude orange powder of deuterated squaramide polymer. In order to remove the deuterated squaramide polymer in an oligomeric state and the unreacted raw materials, the obtained powder is further placed in a Soxhlet extractor, an extraction solvent B is added, the air in the reaction system is replaced with nitrogen, and after replacement for 3-5 times, the reaction system is sealed, stirred and heated to the extraction temperature, and after extraction for a period of time, the stirring is stopped and the mixture is naturally cooled to room temperature, filtered, and vacuum dried to obtain an orange powder of deuterated squaramide polymer.

[0007] The molar ratio of p-phenylenediamine-d4, diethyl squarate and the reaction solvent is 1:1:100-300;

[0008] The reaction solvent A is a 1:1 mixed solution of toluene and chloroform-d, or a 1:1 mixed solution of toluene and acetonitrile-d3;

[0009] The reaction temperature is 90-130°C; the reaction time is 9-16h;

[0010] The extraction solvent B is one of tetrahydrofuran and chloroform-d;

[0011] The extraction temperature is 70-90°C; the extraction time is 24-48h;

[0012] The vacuum drying temperature is 60-90°C.

[0013] The present invention discloses a method for preparing a nitrogen dioxide resistive sensor device based on such organic semiconductor materials. The steps are as follows:

[0014] Step 1, ultrasonically cleaning the interdigital electrodes using water, ethanol and acetone in sequence;

[0015] Step 2: ultrasonically disperse a certain amount of deuterated p-phenylenediamine squaryl amide polymer in solvent C to obtain dispersion D. The mass ratio of the deuterated p-phenylenediamine squaryl amide polymer to the solvent is 1:400-600; the solvent C is one or more of deuterated ethanol, deuterated chloroform, and deuterated acetone, preferably deuterated chloroform; the ultrasonic time is 2-10 minutes;

[0016] Step 3: Apply the dispersion D on the interdigital electrode, place it at room temperature, remove the solvent, and place it in an oven to dry to obtain a deuterated p-phenylenediamine square acid amide polymer sensor that can be used for low-concentration nitrogen dioxide. The brushing is completed with a brush pen, and the number of brushing times is 5 to 10. After each brushing, brush again after the surface is dried; the interdigital electrode mainly includes an aluminum oxide substrate and a silver-palladium alloy electrode, the interdigital width is 50-100μm, the interdigital spacing is 200-300μm, the aluminum oxide substrate thickness is 1 to 2mm, and the silver-palladium alloy electrode thickness is 100 to 200nm. The drying temperature is 50-80℃, and the drying time is 0.5-2h.

[0017] The invention also discloses the application of the deuterated p-phenylenediamine-based squarylamide polymer sensor in the detection of nitrogen dioxide.

[0018] Beneficial Effects

[0019] (1) The device preparation disclosed in the present invention is achieved by brush coating, which is simple and convenient to operate and is conducive to large-scale preparation of devices;

[0020] (2) Since the sensing material disclosed in the present invention has a moderate interaction ability with nitrogen dioxide, the prepared device has a short response time and can detect nitrogen dioxide at the ppb level, with a low detection limit and a higher response than common metal oxides.

[0021] (3) The isotope substitution method disclosed in the present invention can affect physical properties such as polarity, polarizability and molecular volume without directly changing the chemical properties, thereby regulating non-covalent interactions (such as hydrogen bonds, ion-dipole attractions, etc.), thereby achieving better sensitivity while maintaining response / recovery capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the infrared characterization data diagram;

[0023] Figure 2 It is a two-dimensional solid NMR characterization image;

[0024] Figure 3 The device performance test results are shown in Figure 2. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0026] It should be noted that, in the absence of conflict, the embodiments and features of the present invention may be combined with each other.

[0027] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The described embodiments are only part of the embodiments but not all of them. The following description of the exemplary embodiments is merely illustrative and is by no means intended to limit the present invention and its application or use. All other embodiments obtained by ordinary technicians in the field without creative work based on the embodiments of the present invention are within the scope of protection of the present invention.

[0028] Example 1

[0029] (1) Synthesis of deuterated p-phenylenediamine squarylamide polymer

[0030]

[0031] Weigh deuterated p-phenylenediamine (0.56g, 5mmol.), diethyl squarate (0.85g, 5mmol), toluene (46.1g, 0.5mol) and acetonitrile (20.5g, 0.5mol) and place them in a single-mouth pressure-resistant bottle. After loading the reflux device, replace the air in the reaction system with nitrogen four times. Then heat it to 125℃, turn on the stirring device, and reflux for 12h. After the reaction is complete, wait for the temperature to drop to room temperature, filter the product and dry it in a vacuum oven at 70℃ to obtain an orange powder crude product. Then use a Soxhlet extractor to purify the obtained crude product, and the selected extractant is tetrahydrofuran. After the crude product is loaded into the Soxhlet extractor, replace the air in the reaction system with nitrogen four times. Heat it to 65℃, turn on the stirring device, reflux for 36h, wait for the temperature to drop to room temperature, filter the product and dry it in a vacuum oven at 65℃ to obtain 0.76g of orange powder (yield 73.1%).

[0032] The identification data is as follows:

[0033] Infrared spectrum (attached Figure 1 ) shows that the carbonyl absorption peaks of the raw material diethyl squarate and the product have shifted, and the amino absorption peak disappears, proving the occurrence of polymerization reaction. Figure 2 ) showed that the chemical environments of carbon in the product corresponded one to one with the structure, proving the correctness of the structure and the deuteration rate of 93.2%.

[0034] (2) Preparation of sensor:

[0035] Step 1: Use 10 ml of water, ethanol and acetone to ultrasonically clean the interdigital electrodes in order, and then dry them for later use;

[0036] Step 2: ultrasonically add 4 mg of deuterated p-phenylenediamine squaryl amide polymer to 2 g of deuterated chloroform, and ultrasonically disperse for 5 minutes to obtain a deuterated chloroform dispersion containing the deuterated p-phenylenediamine squaryl amide polymer;

[0037] Step 3: Apply the dispersion on the interdigital electrodes 8 times, and apply again after the surface is dry after each application. After application, place it at room temperature, and after the deuterium is evaporated, place it in an oven at 60°C for 1 hour to obtain a deuterated p-phenylenediamine squaramide polymer sensor with a film thickness of 300 μm.

[0038] (3) Current response measurement of nitrogen dioxide sensor based on deuterated p-phenylenediamine squarylamide polymer at different concentrations of nitrogen dioxide:

[0039] First, the device was placed in pure nitrogen conditions. After the current stabilized, the device was placed in nitrogen dioxide atmospheres of different concentrations. After the current stabilized, the device was placed in pure nitrogen conditions again and the above cycle was repeated. The results are as follows: Figure 3 As shown. It can be concluded that the sensor based on deuterated p-phenylenediamine squarylamide polymer can have a good response and recovery performance to nitrogen dioxide as low as 60ppb, and is equivalent to the non-deuterated p-phenylenediamine squarylamide polymer, and its response value is larger. In each concentration range, its response value is about 5 times that of the latter.

[0040] Example 2

[0041] (1) Synthesis of deuterated p-phenylenediamine squarylamide polymer

[0042]

[0043] Weigh deuterated p-phenylenediamine (1.12g, 10mmol.), diethyl squarate (1.90g, 10mmol), toluene (92.2g, 1mol) and tetrahydrofuran (41g, 1mol) and place them in a single-mouth pressure-resistant bottle. After loading the reflux device, replace the air in the reaction system with nitrogen four times. Then heat it to 115℃, turn on the stirring device, and reflux for 16h. After the reaction is complete, wait for the temperature to drop to room temperature, filter the product and dry it in a vacuum oven at 80℃ to obtain an orange powder crude product. Then use a Soxhlet extractor to purify the obtained crude product, and the selected extractant is tetrahydrofuran. After the crude product is loaded into the Soxhlet extractor, replace the air in the reaction system with nitrogen four times. Heat it to 70℃, turn on the stirring device, reflux for 36h, wait for the temperature to drop to room temperature, filter the product and dry it in a vacuum oven at 70℃ to obtain 1.56g of orange powder (yield 75.3%).

[0044] (2) Preparation of sensor:

[0045] Step 1: Use 10 ml of water, ethanol and acetone to ultrasonically clean the interdigital electrodes in order, and then dry them for later use;

[0046] Step 2: ultrasonically add 4 mg of deuterated p-phenylenediamine squaryl amide polymer to 2 g of deuterated ethanol, and ultrasonically disperse for 5 minutes to obtain a deuterated chloroform dispersion containing the deuterated p-phenylenediamine squaryl amide polymer;

[0047] Step 3: Apply the dispersion on the interdigital electrodes 8 times, and apply again after the surface is dry after each application. After application, place it at room temperature, and after the deuterium evaporates, place it in an oven at 70°C for 1 hour to obtain a deuterated p-phenylenediamine squaramide polymer sensor with a film thickness of 300 μm.

[0048] (3) Current response measurement of nitrogen dioxide sensor based on deuterated p-phenylenediamine squarylamide polymer at different concentrations of nitrogen dioxide:

[0049] First, the device was placed in pure nitrogen conditions. After the current stabilized, the device was placed in a nitrogen dioxide atmosphere of different concentrations. After the current stabilized, the device was placed in pure nitrogen conditions again. The above cycle was repeated. The results are shown below. It can be concluded that the deuterated p-phenylenediamine-based square acid amide polymer sensor can have a good response and recovery performance to nitrogen dioxide as low as 60ppb, and is equivalent to the non-deuterated p-phenylenediamine-based square acid amide polymer, and its response value is larger. In each concentration range, its response value is about 4.6 times that of the latter.

[0050] Example 1

[0051] (1) Synthesis of deuterated p-phenylenediamine squarylamide polymer

[0052]

[0053] Weigh deuterated p-phenylenediamine (0.22g, 2mmol.), diethyl squarate (0.34g, 5mmol), toluene (23.1g, 0.25mol) and tetrahydrofuran (10.3g, 0.25mol) and place them in a single-mouth pressure-resistant bottle. After loading the reflux device, replace the air in the reaction system with nitrogen four times. Then heat it to 130℃, turn on the stirring device, and reflux for 16h. After the reaction is complete, wait for the temperature to drop to room temperature, filter the product and dry it in a vacuum oven at 60℃ to obtain an orange powder crude product. Then use a Soxhlet extractor to purify the obtained crude product, and the selected extractant is tetrahydrofuran. After the crude product is loaded into the Soxhlet extractor, replace the air in the reaction system with nitrogen four times. Heat it to 115℃, turn on the stirring device, reflux for 36h, wait for the temperature to drop to room temperature, filter the product and dry it in a vacuum oven at 60℃ to obtain 0.76g of orange powder (yield 73.1%).

[0054] (2) Preparation of sensor:

[0055] Step 1: Use 10 ml of water, ethanol and acetone to ultrasonically clean the interdigital electrodes in order, and then dry them for later use;

[0056] Step 2: ultrasonically add 4 mg of deuterated p-phenylenediamine squaryl amide polymer to 2 g of deuterated acetone, and ultrasonically disperse for 5 minutes to obtain a deuterated chloroform dispersion containing the deuterated p-phenylenediamine squaryl amide polymer;

[0057] Step 3: Apply the dispersion on the interdigital electrodes 8 times, and apply again after the surface is dry after each application. After application, place it at room temperature, and after the deuterium is evaporated, place it in an oven at 60°C for 1 hour to obtain a deuterated p-phenylenediamine squaramide polymer sensor with a film thickness of 300 μm.

[0058] (3) Current response measurement of nitrogen dioxide sensor based on deuterated p-phenylenediamine squarylamide polymer at different concentrations of nitrogen dioxide:

[0059] First, the device was placed in pure nitrogen conditions. After the current stabilized, the device was placed in nitrogen dioxide atmospheres of different concentrations. After the current stabilized, the device was placed in pure nitrogen conditions again and the above cycle was repeated. The results are as follows: Figure 3 As shown. It can be concluded that the sensor based on deuterated p-phenylenediamine squarylamide polymer can have a good response and recovery performance to nitrogen dioxide as low as 60ppb, and is equivalent to the non-deuterated p-phenylenediamine squarylamide polymer, and its response value is larger. In each concentration range, its response value is about 4.6 times that of the latter.

[0060] The specific description above further illustrates the purpose, technical solutions and beneficial effects of the invention in detail. It should be understood that the above is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for improving the performance of a p-phenylenediamine-based squarylamide polymer nitrogen dioxide resistive sensor using the isotope effect, characterized in that: The steps include: Step 1, ultrasonically cleaning the interdigital electrodes with water, ethanol and acetone respectively; Step 2: ultrasonically dispersing a certain amount of deuterated p-phenylenediamine squaryl amide polymer in a solvent to obtain a dispersion; the mass ratio of the deuterated p-phenylenediamine squaryl amide polymer to the solvent is 1:400-600; the solvent is one or more of deuterated ethanol, deuterated chloroform, and deuterated acetone; Step 3: Apply the dispersion onto the interdigital electrodes by brushing, place at room temperature, remove the solvent, and dry in an oven to obtain a deuterated p-phenylenediamine-based square acid amide polymer sensor that can be used for low-concentration nitrogen dioxide.

2. The method according to claim 1, characterized in that: The brushing in step 3 is completed by using a brush pen, and the brushing times are 5 to 10 times. After each brushing, brush again after the surface is dry; the interdigital electrode mainly includes an aluminum oxide substrate and a silver-palladium alloy electrode, the interdigital width is 50-100μm, and the interdigital spacing is 200-300μm; the drying temperature is 50-80℃, and the drying time is 0.5-2h.

3. The method according to claim 1, characterized in that: The preparation method of the deuterated p-phenylenediamine-based square acid amide polymer; the preparation method is as follows: Step 1, add a certain amount of p-phenylenediamine-d4, diethyl squarate and reaction solvent A to a single-mouth pressure-resistant bottle equipped with a condensing device, then replace the air in the reaction system with nitrogen, after the replacement is completed, seal the reaction system, stir and heat to the reaction temperature, after reacting for a period of time, stop stirring and naturally cool to room temperature, filter, and vacuum dry to obtain a deuterated squarylamide polymer orange powder crude product; the molar ratio of p-phenylenediamine-d4, diethyl squarate and the reaction solvent is 1:1:100-300; The reaction solvent A is a 1:1 mixed solution of toluene and chloroform-d, or a 1:1 mixed solution of toluene and acetonitrile-d3; Step 2, placing the crude product in a Soxhlet extractor, adding extraction solvent B, replacing the air in the reaction system with nitrogen, then sealing the reaction system, stirring and heating to the extraction temperature, after extraction for a period of time, stopping stirring and naturally cooling to room temperature, filtering, and vacuum drying to obtain deuterated square acid amide polymer orange powder; the extraction solvent B is tetrahydrofuran or chloroform-d; The reaction temperature in step 1 is 90-130°C; the reaction time is 9-16h; The extraction temperature in step 2 is 70-90°C; the extraction time is 24-48h; The vacuum drying temperature in step 2 is 60-90°C.

4. The method according to claim 2, characterized in that: The thickness of the aluminum oxide substrate is 1 to 2 mm, and the thickness of the silver-palladium alloy electrode is 100 to 200 nm.

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