Conjugated microporous polymers, films and their preparation and use
Conjugated microporous polymer films were prepared by a one-step substitution reaction involving 3,4-dihydroxy-3-cyclobutene-1,2-dione and donor molecules, along with electrospray technology. This solved the problems of poor processability and high cost, and enabled highly responsive and selective sensing applications for toxic gases such as NO2.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DONGHUA UNIV
- Filing Date
- 2023-05-18
- Publication Date
- 2026-06-05
AI Technical Summary
Existing conjugated microporous polymers are difficult to process, and their synthesis methods are costly, requiring catalysts and strictly anhydrous and oxygen-free environments.
Conjugated microporous polymers were prepared by combining 3,4-dihydroxy-3-cyclobutene-1,2-dione with donor molecules of different properties via a simple one-step substitution reaction, and then thin films were prepared by electrospraying.
A low-cost, easy-to-process conjugated microporous polymer film has been developed, which exhibits high responsiveness and selectivity to toxic gases such as NO2 at room temperature, making it suitable for gas sensors.
Smart Images
Figure CN116751349B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of microporous polymers, and specifically relates to a conjugated microporous polymer, a thin film, and their preparation and application. Background Technology
[0002] Gas sensors, as core components of olfactory sensing, can detect the type and concentration of gases and have broad application prospects in environmental monitoring, public safety, medical and health care, food safety, and military aerospace. With the development of information technologies such as the Internet of Things and the Internet, artificial olfaction technology built using gas sensors and artificial intelligence algorithms is playing an increasingly important role in more fields. Therefore, developing gas sensors with high sensitivity, high selectivity, high stability, and fast response recovery is a primary goal. Gas-sensitive materials are the core of gas sensors, determining their various performance characteristics. In recent years, conjugated microporous polymers (CMPs), as an emerging type of organic porous material, have attracted increasing attention in the field of chemical sensing due to their high physicochemical stability, functional regulation, environmental stability, simple preparation routes, and versatility. CMPs are mainly prepared by bonding conjugated monomers with different topological sequences (such as C2, C3, C4, and C6) through metal coupling reactions (such as Yamamoto, Suzuki, and Sonogashira reactions), oxidative coupling reactions, and cyclization reactions. However, these synthetic reactions typically require catalysts or extremely strict anhydrous and oxygen-free environments, making the experiments expensive. Therefore, developing a catalyst-free, low-cost, and simple-to-operate method is of great significance. Furthermore, conjugated microporous polymers suffer from insolubility and infusibility. Overcoming the problem of poor processability and developing a practical conjugated microporous polymer membrane has significant application potential. Summary of the Invention
[0003] The technical problem to be solved by this invention is to provide a conjugated microporous polymer, a thin film, and its preparation and application. The method provided by this invention solves the problem of poor processability of conjugated microporous polymers, offering a simple and low-cost approach. 3,4-Dihydroxy-3-cyclobutene-1,2-dione, as an acceptor molecule, binds to three donor molecules with different properties to construct conjugated microporous polymers with different configurations, thereby enabling applications in the field of sensing.
[0004] This invention discloses a conjugated microporous polymer based on 3,4-dihydroxy-3-cyclobutene-1,2-dione, wherein the conjugated microporous polymer has the following structure:
[0005]
[0006] At least one of them.
[0007] The present invention discloses a method for preparing a conjugated microporous polymer based on 3,4-dihydroxy-3-cyclobutene-1,2-dione, comprising:
[0008] 3,4-Dihydroxy-3-cyclobutene-1,2-dione, monomer, and solvent were mixed, refluxed, purified, and dried to obtain a powdered conjugated microporous polymer based on 3,4-dihydroxy-3-cyclobutene-1,2-dione; wherein the monomer is at least one of 1,3,5-tris(4-aminophenyl)benzene, 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, and tris(4-aminophenyl)amine.
[0009] The preferred embodiment of the above preparation method is as follows:
[0010] The molar ratio of the 3,4-dihydroxy-3-cyclobutene-1,2-dione to the monomer is 1:2 to 2:1.
[0011] Furthermore, the molar ratio of 3,4-dihydroxy-3-cyclobutene-1,2-dione and 1,3,5-tris(4-aminophenyl)benzene is 1:2 to 2:1.
[0012] The molar ratio of 3,4-dihydroxy-3-cyclobutene-1,2-dione and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine is 1:2 to 2:1.
[0013] The molar ratio of 3,4-dihydroxy-3-cyclobutene-1,2-dione to tris(4-aminophenyl)amine is 1:2 to 2:1.
[0014] The solvent is n-butanol; the mass ratio of the 3,4-dihydroxy-3-cyclobutene-1,2-dione to the solvent is (0.4-0.9):100.
[0015] The reflux reaction is carried out in a solvent through a condensation cycle.
[0016] The reflux reaction is a condensation reflux, stirred under oil bath heating conditions of 110-130℃, and the reaction duration is 12-16h.
[0017] Furthermore, the reflux reaction temperature is 120°C, and the preferred reaction time is 14 hours.
[0018] The purification process involves Soxhlet extraction, specifically: the product is washed sequentially with methanol, acetone, and tetrahydrofuran solvents using the Soxhlet extraction method until the washing solvents are transparent. The Soxhlet extraction time for each solvent is 24–48 hours, resulting in a powdered conjugated microporous polymer.
[0019] The drying process is vacuum drying, with a temperature of 80–100°C and a time of 48–72 hours.
[0020] The present invention discloses a conjugated polymer membrane, wherein the conjugated polymer membrane is obtained by electrospraying technology using a raw material (electroplated liquid) containing the conjugated microporous polymer of claim 1, polyvinylidene fluoride and N,N-dimethylformamide.
[0021] A method for preparing a conjugated polymer film according to the present invention includes:
[0022] The conjugated microporous polymer, polyvinylidene fluoride, and N,N-dimethylformamide are mixed and sprayed onto a substrate using electrospraying technology to obtain a conjugated polymer film.
[0023] The mass ratio of the conjugated microporous polymer, polyvinylidene fluoride, and N,N-dimethylformamide is 2:1:18 to 6:1:18; the substrate is a paper substrate.
[0024] The process parameters for the electro-injection are as follows: the speed of the main micro-pump for electro-injection is 0.8–1.6 ml / h, the voltage of the medium negative pressure power supply is 2–8 kV, and the voltage of the positive pressure power supply is 8–12 kV.
[0025] The conjugated microporous polymer provided by this invention is an N-type semiconductor. The polymer film prepared from it has the advantages of low synthesis cost and ease of preparation. It responds to a variety of toxic and harmful gases at room temperature, with the best response to NO2 and excellent selectivity. It can be used as a gas-sensitive material to prepare gas sensors and has application value in the field of chemical sensing.
[0026] Beneficial effects
[0027] (1) This invention provides a method for synthesizing a conjugated microporous polymer membrane based on 3,4-dihydroxy-3-cyclobutene-1,2-dione. The method involves a simple one-step substitution reaction of 3,4-dihydroxy-3-cyclobutene-1,2-dione with 1,3,5-tris(4-aminophenyl)benzene, 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, or tris(4-aminophenyl)amine to obtain the conjugated microporous polymer having the structures shown in Formulas I, II, and III. The powder is then formulated into a liquid and prepared into a membrane via simple electrospraying.
[0028] (2) The conjugated microporous polymer membranes based on 3,4-dihydroxy-3-cyclobutene-1,2-dione with different configurations synthesized in this invention have potential application value in the field of chemical sensing.
[0029] (3) The conjugated microporous polymer membrane prepared by this invention enables the detection of NO2 at room temperature. Its preparation method is green, simple and inexpensive, and overcomes the problem of difficult processability of conjugated microporous polymers, and has good prospects for sensing applications. Attached Figure Description
[0030] Figure 1 The product obtained in Example 1 13 C-NMR;
[0031] Figure 2 A photograph of the product obtained in Example 1;
[0032] Figure 3 The image shows the SEM morphology of the product obtained in Example 1.
[0033] Figure 4 The product obtained in Example 3 13 C-NMR;
[0034] Figure 5 Here is a photograph of the product obtained in Example 3;
[0035] Figure 6 Here is a SEM image of the product obtained in Example 3;
[0036] Figure 7 The product obtained in Example 5 13 C-NMR;
[0037] Figure 8 Here is a photograph of the product obtained in Example 5;
[0038] Figure 9 Here is a SEM image of the product obtained in Example 5;
[0039] Figure 10 The selectivity of the products obtained in Examples 2, 4 and 6 to different gases at room temperature. Detailed Implementation
[0040] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.
[0041] 3,4-Dihydroxy-3-cyclobutene-1,2-dione (Beijing Inokai Co., Ltd.), 1,3,5-tris(4-aminophenyl)benzene (Biode Pharmaceutical Co., Ltd.), 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (Shanghai Aladdin Biochemical Technology Co., Ltd.), tris(4-aminophenyl)amine (Leyan Reagent Co., Ltd.), n-Butanol (Sinopharm Chemical Reagent Co., Ltd.)
[0042] Example 1
[0043] 3,4-Dihydroxy-3-cyclobutene-1,2-dione (570 mg, 5 mmol) and 1,3,5-tris(4-aminophenyl)benzene (597.5 mg, 1.7 mmol) were added to a single-necked flask, along with 80 mL of n-butanol as the reaction solvent. The reaction was carried out under reflux and heated in an oil bath at 120 °C for 14 h. Soxhlet extraction was performed sequentially with acetone, methanol, and tetrahydrofuran until the filtrate was colorless. After washing, the filtrate was dried in a vacuum oven at 80 °C for 48 h to obtain the conjugated microporous polymer based on 3,4-dihydroxy-3-cyclobutene-1,2-dione, denoted as SQCMP1. Then, SQCMP1 and polyvinylidene fluoride:N,N-dimethylformamide were prepared into an electrospray liquid at a mass ratio of 3:1:18. The electrospray liquid was then placed into an electrospinning device, and the substrate was uniformly coated on the rotating roller receiver. Under the conditions of an electrospray ambient temperature of 25℃, a negative voltage of 5kV, a positive voltage of 12kV, a receiving distance of 12cm between the receiver and the spinneret, a flow rate of 0.8mL / h, and a receiver rotation speed of 100rpm, the electrospray liquid was sprayed onto the surface of the substrate material through the nozzle to form a film.
[0044] The product obtained in this example 13 C-NMR such as Figure 1 As shown, solid-state carbon NMR spectrum showed characteristic peaks of C(1) and C(2) in the four-membered ring structure of 3,4-dihydroxy-3-cyclobutene-1,2-dione at ~170 ppm, and characteristic peaks of CN in the four-membered ring structure of 3,4-dihydroxy-3-cyclobutene-1,2-dione connected to amino monomer at ~140 ppm.
[0045] The SEM images and SEM images of the product obtained in this example are as follows: Figure 2 , 3 As shown, it appears as a yellow film on a macroscopic scale, and as a blocky mass composed of small particles with diameters ranging from 0.1 to 0.5 μm on a microscopic scale.
[0046] Example 2
[0047] The SQCMP1 gas detection method is as follows:
[0048] Two Pt wires were connected to both ends of the SQCMP1-based membrane using silver paste, and then the Pt wires were connected to the test element. Tests were performed at 100 ppm for different gases at room temperature.
[0049] Example 3
[0050] 3,4-Dihydroxy-3-cyclobutene-1,2-dione (570 mg, 5 mmol) and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (602.5 mg, 1.7 mmol) were added to a single-necked flask, along with 80 mL of n-butanol as the reaction solvent. The reaction was carried out under reflux and heated in an oil bath at 120 °C for 14 h. Soxhlet extraction was performed sequentially with acetone, methanol, and tetrahydrofuran until the filtrate was colorless. After washing, the filtrate was dried in a vacuum oven at 80 °C for 48 h to obtain the conjugated microporous polymer based on 3,4-dihydroxy-3-cyclobutene-1,2-dione, denoted as SQCMP2. Then, SQCMP2 and polyvinylidene fluoride:N,N-dimethylformamide were prepared into an electrospray liquid at a mass ratio of 3:1:18. The electrospray liquid was then placed into an electrospinning device, and the substrate was uniformly coated on the rotating roller receiver. Under the conditions of an electrospray ambient temperature of 25℃, a negative voltage of 5kV, a positive voltage of 11kV, a receiving distance of 15cm between the receiving device and the spinneret, a flow rate of 1.0mL / h, and a receiver rotation speed of 100rpm, the electrospray liquid was sprayed onto the surface of the substrate material through the nozzle to form a film.
[0051] The product obtained in this example 13 C-NMR such as Figure 4 As shown, solid-state carbon NMR spectrum showed characteristic peaks of C(1) and C(2) in the four-membered ring structure of 3,4-dihydroxy-3-cyclobutene-1,2-dione at ~170 ppm, and characteristic peaks of CN in the four-membered ring structure of 3,4-dihydroxy-3-cyclobutene-1,2-dione connected to amino monomer at ~140 ppm.
[0052] The SEM images and SEM images of the product obtained in this example are as follows: Figure 5 , 6 As shown, the macroscopically orange membrane is composed of strips with diameters ranging from 0.5 to 1.2 μm.
[0053] Example 4
[0054] The SQCMP2 gas detection method is as follows:
[0055] Two Pt wires were connected to both ends of the SQCMP2-based membrane using silver paste, and then the Pt wires were connected to the test element. Tests were performed at 100 ppm for different gases at room temperature.
[0056] Example 5
[0057] 3,4-Dihydroxy-3-cyclobutene-1,2-dione (570 mg, 5 mmol) and tris(4-aminophenyl)amine (493.6 mg, 1.7 mmol) were added to a single-necked flask, along with 80 mL of n-butanol as the reaction solvent. The reaction was carried out under reflux and heated in an oil bath at 120 °C for 14 h. Soxhlet extraction was performed sequentially with acetone, methanol, and tetrahydrofuran until the filtrate was colorless. After washing, the filtrate was dried in a vacuum oven at 80 °C for 48 h to obtain the conjugated microporous polymer based on 3,4-dihydroxy-3-cyclobutene-1,2-dione, denoted as SQCMP3. Then, SQCMP3 and polyvinylidene fluoride:N,N-dimethylformamide were prepared into an electrospray solution at a mass ratio of 3:1:18. The electrospray solution was then placed into an electrospinning device, and the substrate was uniformly coated on the rotating roller receiver. Under the conditions of an electrospray environment temperature of 25℃, a negative voltage of 4kV, a positive voltage of 12kV, a receiving distance of 14cm between the receiver and the spinneret, a flow rate of 1.5mL / h, and a receiver rotation speed of 100rpm, the electrospray solution was sprayed onto the surface of the substrate material through the nozzle to form a film.
[0058] The product obtained in this example 13 C-NMR such as Figure 7 As shown, solid-state carbon NMR spectrum showed characteristic peaks of C(1) and C(2) in the four-membered ring structure of 3,4-dihydroxy-3-cyclobutene-1,2-dione at ~170 ppm, and characteristic peaks of CN in the four-membered ring structure of 3,4-dihydroxy-3-cyclobutene-1,2-dione connected to amino monomer at ~140 ppm.
[0059] The SEM images and SEM images of the product obtained in this example are as follows: Figure 8 , 9 As shown, the film appears red macroscopically, but is composed of blocky particles with a particle size ranging from 0.8 to 1 μm.
[0060] Example 6
[0061] The SQCMP3 gas detection method is as follows:
[0062] Two Pt wires were connected to both ends of the SQCMP3-based membrane using silver paste, and then the Pt wires were connected to the test element. Tests were performed at 100 ppm for different gases at room temperature.
[0063] The response graphs of Examples 2, 4, and 6 are as follows: Figure 10 As shown, the response to 10 toxic and harmful gases at room temperature demonstrates that this type of material has a good response to NO2 and exhibits excellent selectivity.
Claims
1. A conjugated polymer film, characterized in that, The conjugated polymer membrane is obtained by electro-spraying technology using raw materials containing a conjugated microporous polymer based on 3,4-dihydroxy-3-cyclobutene-1,2-dione, polyvinylidene fluoride, and N,N-dimethylformamide. The conjugated microporous polymer structure based on 3,4-dihydroxy-3-cyclobutene-1,2-dione is as follows: The process parameters for the electro-injection are as follows: the speed of the main micro-pump for electro-injection is 0.8~1.6 ml / h, the voltage of the medium negative pressure power supply is 2~8 kV, and the voltage of the positive pressure power supply is 8~12 kV.
2. The conjugated polymer film according to claim 1, characterized in that, The method for preparing the conjugated microporous polymer based on 3,4-dihydroxy-3-cyclobutene-1,2-dione includes: 3,4-Dihydroxy-3-cyclobutene-1,2-dione, monomer, and solvent were mixed, refluxed, purified, and dried to obtain a conjugated microporous polymer based on 3,4-dihydroxy-3-cyclobutene-1,2-dione; wherein the monomer was 2,4,6-tris(4-aminophenyl)-1,3,5-triazine.
3. The conjugated polymer film according to claim 2, characterized in that, The molar ratio of the 3,4-dihydroxy-3-cyclobutene-1,2-dione to the monomer is 1:2 to 2:1; the solvent is n-butanol; and the mass ratio of the 3,4-dihydroxy-3-cyclobutene-1,2-dione to the solvent is (0.4 to 0.9):
100.
4. The conjugated polymer membrane according to claim 2, characterized in that, The reflux reaction is a condensation reflux, stirred under oil bath heating conditions of 110~130 ℃, and the reaction duration is 12~16 h.
5. The conjugated polymer film according to claim 2, characterized in that, The purification is carried out by Soxhlet extraction, specifically: the product is washed sequentially with methanol, acetone and tetrahydrofuran solvents using the Soxhlet extraction method, with the extraction time for each solvent being 24-48 h; the drying is carried out by vacuum drying at a temperature of 80-100℃ for 48-72 h.
6. A method for preparing the conjugated polymer film according to claim 1, comprising: A conjugated microporous polymer based on 3,4-dihydroxy-3-cyclobutene-1,2-dione, polyvinylidene fluoride, and N,N-dimethylformamide were mixed and sprayed onto a substrate using electrospray technology to obtain a conjugated polymer film. The electrospray process parameters were as follows: the speed of the main micropump was 0.8~1.6 ml / h, the voltage of the medium negative voltage power supply was 2~8 kV, and the voltage of the positive voltage power supply was 8~12 kV.
7. The preparation method according to claim 6, characterized in that, The mass ratio of the conjugated microporous polymer based on 3,4-dihydroxy-3-cyclobutene-1,2-dione, polyvinylidene fluoride, and N,N-dimethylformamide is 2:1:18 to 6:1:18; the substrate is a paper substrate.
8. The application of the conjugated polymer membrane of claim 1 in the field of chemical sensing.