A perylene imide-based covalent organic polymer film and its preparation method and application

Abstract

The present invention discloses a perylene imide covalent organic polymer film material and a preparation method, and also relates to an application of the organic polymer film in trimethylamine gas sensing. The present invention provides a liquid-liquid interface polymerization method to prepare a covalent organic polymer film, and transfers the film to an ITO interdigital electrode to prepare a trimethylamine gas sensor. The present invention obtains a sensor with excellent gas-sensitive performance, which has the advantages of good responsiveness, high sensitivity, fast response and recovery time, good reproducibility, and strong selectivity to trimethylamine of different concentrations; and the preparation is simple, the production cost is low, and it is green and environmentally friendly, and can be used for the detection of low-concentration trimethylamine in the environment.

Description

Technical Field

[0001] The present invention relates to the technical field of preparation and application of composite material interface reaction, and in particular to a preparation method of a perylene diimide-based covalent organic polymer film material (PDI-COP) and an application in detecting trimethylamine. Background Art

[0002] Trimethylamine (TMA) is a volatile organic compound (VOC) that is a colorless liquefied gas with a fishy ammonia smell. It is soluble in water, ethanol and ether. It is flammable. TMA is very harmful to human health, such as eye irritation, headache, breathing difficulties, lung infection, and even death. Trimethylamine can also be secreted by microorganisms containing nitrogen oxides produced during the deterioration of dead fish and marine life. The concentration and proportion of trimethylamine can be used as an effective indicator to evaluate the freshness of fish and seafood. Nowadays, in order to ensure that the quality of fish and seafood products during cold chain transportation meets the requirements of consumers, it is of great value to monitor and predict the quality of fish and seafood products during transportation and storage in real time.

[0003] At present, gel chromatography, electrochemical analysis, colorimetry and other methods are commonly used to detect trimethylamine gas in the environmental field. However, their large size, high price, and inability to detect in real time limit their application in real life. At the same time, various chemical impedance gas sensors based on metal oxide semiconductors usually require high operating temperatures, which limits their practical application. Ambient humidity is also a challenge for metal oxide gas sensors, which can produce erroneous responses and thus unreliable results. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing a perylene imide-based covalent organic polymer film material for detecting trimethylamine, characterized in that the method comprises the following steps:

[0005] (1) Dissolve 1,6,7,12-tetrachloro-3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) in chloroform as the lower organic layer, then slowly add pure water to the upper surface of the solution, leaving a stable chloroform / water interface. Subsequently, dissolve trihydrazinotriazine (THSTZ) and p-toluenesulfonic acid (PTSA) in dimethyl sulfoxide as the upper organic layer and slowly add them to the beaker. React at room temperature for 36-72 h, wherein the mass ratio of PTCDA, THSTZ, and PTSA is 5:1.1-1.6:0.1-0.3, the volume ratio of chloroform, dimethyl sulfoxide, and deionized water is 1:0.3-0.5:1-1.2, and the volume is 125-145 mL;

[0006] (2) After the reaction is completed, the mixture is washed with deionized water several times. A light yellow smooth film is clearly observed at the interface between the two phases, which is the perylene imide-based covalent organic polymer film material.

[0007] Wherein, the perylene diimide-based covalent organic polymer film is referred to as PDI-COP, and its structural formula is shown in Formula 1;

[0008] Formula 1

[0009] Application of the perylene imide-based covalent organic polymer film material in the preparation of a trimethylamine gas sensor.

[0010] A gas sensor for detecting trimethylamine comprises an ITO conductive glass substrate, the ITO conductive glass substrate is etched into ITO interdigital electrodes, and a perylene imide-based covalent organic polymer film PDI-COP is arranged on the surface of the ITO interdigital electrodes.

[0011] The preparation method for constructing a gas-sensitive sensor for detecting trimethylamine is as follows:

[0012] (1) Preparation of ITO conductive glass interdigital electrodes: taking ITO conductive glass, cleaning, drying, and then etching the ITO conductive glass substrate into ITO interdigital electrodes (the prior art);

[0013] The specific method of treating the ITO interdigital electrode is as follows: placing the ITO interdigital electrode in a beaker, and ultrasonically cleaning it in an ultrasonic cleaner using solvents of different polarities, such as toluene, acetone, anhydrous ethanol, and distilled water, respectively, and cleaning it three times with each solvent for five minutes each time, and then vacuum drying it for standby use;

[0014] (2) The PDI-COP film at the interface is transferred to a transparent conductive film (ITO) interdigital electrode with a glass substrate. The number of transferred film layers is 1-4. After the solvent evaporates, the film is vacuum dried to obtain a gas sensor.

[0015] The present invention prepares a gas sensor for measuring trimethylamine. The material used is a covalent organic polymer film PDI-COP constructed by a perylene dianhydride compound PTCDA and a triazine compound THSTZ. The covalent organic polymer film PDI-COP has the advantages of good responsiveness, high sensitivity, fast response and recovery time, good reproducibility and strong selectivity to trimethylamine in the range of 150-12 ppm at room temperature. Such a covalent organic polymer film exhibits excellent gas-sensing performance.

[0016] Advantages of the present invention:

[0017] (1) The preparation method of the nanomaterial used for detecting trimethylamine used in the present invention is simple and has relatively low energy consumption;

[0018] (2) The gas sensor for detecting trimethylamine of the present invention has the advantage of being able to effectively and quickly measure trimethylamine at room temperature.

[0019] The method has the advantages of low concentration of trimethylamine, fast response and recovery time, good stability, strong anti-interference ability and good selectivity, simple structure and preparation process, low cost and easy to realize industrialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a scanning electron microscopy cross-sectional image of PDI-COP;

[0021] Figure 2 is the Fourier infrared spectrum of PDI-COP;

[0022] Figure 3 is the X-ray diffraction (XPS) spectrum of PDI-COP;

[0023] Figure 4 This is the long-term stability curve of the trimethylamine gas sensor to 80 ppm trimethylamine within 30 days (room temperature condition);

[0024] Figure 5 This is the response / recovery time curve of the trimethylamine gas sensor at 80 ppm trimethylamine (room temperature);

[0025] Figure 6 This is the reproducibility test curve of trimethylamine gas sensor (room temperature condition);

[0026] Figure 7 is the response-time curve of trimethylamine gas sensor to different concentrations of trimethylamine (room temperature condition);

[0027] Figure 8 This is a schematic diagram of the selectivity of trimethylamine gas sensor to different gases. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. However, the content of the present invention is not limited to the following embodiments. The details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0029] It should be understood that the terms used in the examples of the present invention are intended to describe specific embodiments rather than to limit the scope of protection of the present invention. The methods in the following examples where specific conditions are not specified are generally carried out under conventional conditions or under conditions recommended by various manufacturers.

[0030] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise specified in the present invention, the two endpoints of each numerical range and any numerical value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are familiar to those skilled in the art and the description of the present invention. The present invention can also be implemented using any methods, equipment and materials in the prior art that are similar or equivalent to the methods, equipment and materials described in the embodiments of the present invention.

[0031] Example 1 Preparation method of perylene diimide-based covalent organic polymer film PDI-COP 1.1

[0033] (1) Dissolve 0.02 g PTCDA in 50 mL chloroform as the lower organic layer, then slowly add 40 ml pure water to the upper surface of the solution, leaving a stable chloroform / water interface. Subsequently, dissolve 0.0044 g THSTZ and 0.0004 g PTSA in 15 mL dimethyl sulfoxide and 20 mL deionized water as the upper organic layer and slowly add them to the beaker. Perform the interfacial reaction at room temperature for 36 h. After the reaction is completed, wash with deionized water several times, and a light yellow smooth film is clearly observed at the interface of the two phases, which is PDI-COP;

[0034] (2) Comprehensive characterization of the obtained products, Figure 1 This is a scanning electron microscope cross-sectional image of a perylene imido covalent organic polymer thin film material, showing the surface morphology and thickness of the thin film material. Figure 2 As shown in the Fourier transform infrared spectrum, the peaks at 1736-1738 cm -1 The anhydride peak at 3426 cm -1 The amino peak disappears at 1322 cm -1 A new characteristic peak of PDI-COP was found at , indicating that PDI-COP was successfully synthesized. Figure 3 As shown, the XPS spectrum shows that C, N, O, and Cl elements coexist in the structure of perylene imide-based covalent organic polymer film materials. 1.2

[0036] (1) Dissolve 0.02 g PTCDA in 50 mL chloroform as the lower organic layer, then slowly add 40 ml pure water to the upper surface of the solution, leaving a stable chloroform / water interface. Subsequently, dissolve 0.0052 g THSTZ and 0.0008 g PTSA in 20 mL dimethyl sulfoxide and 25 mL deionized water as the upper organic layer and slowly add them to the beaker. Perform the interfacial reaction at room temperature for 54 h. After the reaction is completed, wash with deionized water several times, and a light yellow smooth film is clearly observed at the interface of the two phases, which is PDI-COP;

[0037] (2) Comprehensive characterization of the obtained film product: the results are consistent with 1.1 1.3

[0039] (1) Dissolve 0.02 g of 1,6,7,12-tetrachloro-3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) in 50 mL of chloroform as the lower organic layer, then slowly add 40 ml of pure water to the upper surface of the solution, leaving a stable chloroform / water interface. Subsequently, dissolve 0.0064 g of trihydrazinotriazine and 0.0012 g of p-toluenesulfonic acid in 25 mL of dimethyl sulfoxide and 30 mL of deionized water as the upper organic layer and slowly add them to the beaker. The interfacial reaction was carried out at room temperature for 72 h. After the reaction was completed, the mixture was washed several times with deionized water, and a light yellow smooth film was clearly observed at the interface of the two phases, which was PDI-COP.

[0040] (2) Comprehensive characterization of the obtained film product: the results are consistent with 1.1.

[0041] Example 2 Preparation of trimethylamine gas sensor

[0042] (1) Preparation of ITO conductive glass interdigital electrodes: taking ITO conductive glass, cleaning, drying, and then etching the ITO conductive glass substrate into ITO interdigital electrodes (the prior art);

[0043] (2) The specific method of treating the ITO interdigital electrode is as follows: placing the ITO interdigital electrode in a beaker, and ultrasonically cleaning it in an ultrasonic cleaner using solvents of different polarities, namely toluene, acetone, anhydrous ethanol, and distilled water, respectively, and cleaning it three times with each solvent for five minutes each time, and then vacuum drying it for use;

[0044] (3) The PDI-COP film at the interface is transferred to the interdigital electrode with (ITO). The number of transferred film layers is 2. After the solvent evaporates, the film is vacuum dried to obtain a gas sensor.

[0045] Example 3 Performance Test of Trimethylamine Gas Sensor

[0046] The covalent organic polymer film PDI-COP obtained in Example 2 was selected to construct a gas-sensitive test device, and a gas-sensitive test experiment was carried out. The gas-sensitive test process is carried out in a relatively mild environment (room temperature, external atmospheric pressure and dry air) and under a fixed bias voltage of 5 V between the two electrodes. The test instrument used: Agilent B290a precision source / measurement unit. Among them, the gas sensors prepared using the covalent organic polymer film PDI-COP prepared in Example 2 were tested separately, and the test results were consistent; Figure 4-8 As shown. Figure 5 As shown in Figure 2, the response / recovery times are 96 s and 64 s respectively; Figure 4 and Figure 6 As shown in the figure, the long-term stability of the covalent organic polymer film PDI-COP gas sensor within 30 days is basically consistent with the repeated stability to 80 ppm trimethylamine, indicating that the gas sensor has good stability; Figure 7 As shown in Figure 2, the covalent organic polymer film PDI-COP gas sensor has a good response to 150-12 ppm trimethylamine, and the detection limit can reach 4 ppm; Figure 8 As shown, the covalent organic polymer film PDI-COP gas sensor was tested for gas sensitivity to different gases including 100 ppm including trimethylamine, triethylamine, methanol, ethanol, acetone, acetic acid, ammonia, carbon monoxide and nitric oxide. It can be seen that among various test gases, the covalent organic polymer film PDI-COP showed the greatest response to trimethylamine and had good selectivity for trimethylamine.

[0047] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for preparing a perylene diimide-based covalent organic polymer film material PDI-COP, characterized in that: The following steps are involved: (1) 1,6,7,12-tetrachloro-3,4,9,10-perylenetetracarboxylic acid dianhydride PTCDA was dissolved in chloroform as the lower organic layer, and then pure water was slowly added to the upper surface of the solution to leave a stable chloroform / water interface; then, trihydrazino-s-triazine THSTZ and p-toluenesulfonic acid PTSA were dissolved in dimethyl sulfoxide as the upper organic layer and slowly added to the beaker; the reaction was carried out at room temperature for 36-72 h, wherein the mass ratio of PTCDA, THSTZ, and PTSA was 5: 1.1-1.6: 0.1-0.3, and the total mass was 24.8-27.6 mg; the volume ratio of chloroform, dimethyl sulfoxide, and pure water was 1: 0.3-0.5: 1.2-1.4, and the total volume was 125-145 mL; (2) After the reaction was completed, the sample was washed with deionized water several times. A light yellow smooth film was clearly observed at the interface between the two phases, which was PDI-COP.

2. A perylene diimide-based covalent organic polymer film material PDI-COP, which has the structural characteristic of being a wrinkled film structure with an average thickness of 30 nm.

3. The use of a perylene imide-based covalent organic polymer film material PDI-COP according to claim 2, characterized in that: Used for detection of trimethylamine gas at room temperature.

4. The use of a perylene diimide-based covalent organic polymer film material PDI-COP according to claim 3, characterized in that: In the concentration range of 12-150 ppm, as the concentration of trimethylamine increases, the response current gradually increases, and there is a linear relationship between the concentration of trimethylamine and the current response.

5. The use of a perylene diimide-based covalent organic polymer film material PDI-COP according to claim 3, characterized in that: The detection limit for trimethylamine is 4 ppm.

6. The use of a perylene imido covalent organic polymer film material PDI-COP according to claim 3, characterized in that: The response and recovery times to trimethylamine were 96 s and 63 s, respectively.

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