A method for preparing thiazole-[5,4-d]thiazole covalent triazine polymer materials and their applications

Abstract

This invention discloses a method for preparing a thiazolium-[5,4-d]thiazolium covalent triazine polymer material and its application, belonging to the technical field of porous organic polymer materials. The preparation method of the thiazolium-[5,4-d]thiazolium covalent triazine polymer material of this invention is as follows: A monomer and anhydrous zinc chloride are uniformly mixed and transferred to a glass tube. After cooling with liquid nitrogen, the mixture is melt-sealed under vacuum. The sealed glass tube is then transferred to a muffle furnace for heating and reaction to obtain the product. After the reaction, the product is removed and successively ground, washed, and vacuum-dried to obtain the thiazolium-[5,4-d]thiazolium covalent triazine polymer material. The thiazolium-[5,4-d]thiazolium covalent triazine polymer material of this invention has a simple synthesis, high yield, good stability, low spin density free radicals, and hydrophilicity, making it suitable as a high-performance photothermal conversion material with excellent application prospects in the field of solar water evaporation.

Description

Technical Field

[0001] This invention belongs to the field of porous organic polymer materials technology, specifically relating to a method for preparing a thiazole-[5,4-d]thiazole covalent triazine polymer material and its application. Background Technology

[0002] Solar energy is a clean and renewable energy source, achieving its efficient conversion through photochemical, photovoltaic, and photothermal processes. Over the past few decades, the emergence of photothermal conversion has greatly expanded the utilization of solar-powered domestic hot water, as well as water desalination and purification. Researchers are dedicated to achieving efficient solar steam generation; however, photobleaching and limited solar radiation absorption lead to inefficient photothermal conversion. Preparing materials with broad solar radiation absorption by endowing them with free radical properties is an important strategy for achieving efficient solar steam generation; however, the inherent reactivity and strong electronic interactions of free radicals are often accompanied by instability in aggregated states and unpredictable properties. Therefore, constructing efficient photothermal conversion materials with highly stable and persistent organic free radicals remains a significant challenge.

[0003] Porous organic polymers (POPs), as a novel class of polymer semiconductors, have become highly promising candidates in the field of solar photothermal (SSG) due to their advantages such as light weight, inherent porosity, and low thermal conductivity. However, the inherent hydrophobicity and limited light absorption (especially in the near-infrared region) of POPs are two major bottlenecks hindering their application in SSGs. To address this issue, various post-processing techniques have been employed for POPs, such as carbonization, hybridization, chemical hydrophilic treatment, or post-synthetic modification, to enhance their light absorption and hydrophilicity. However, these methods not only significantly complicate their operation in solar vapor generation but also reduce their long-term stability due to the delamination of the substrate and photothermal material, further complicating their application in SSGs. Therefore, developing a photothermal conversion material with high photothermal conversion efficiency, simple synthesis, and good stability is of great significance. Summary of the Invention

[0004] In view of the defects and deficiencies of the prior art, the purpose of this invention is to provide a method for preparing thiazole-[5,4-d]thiazole covalent triazine polymer materials and their applications.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] The preparation method of the above-mentioned thiazole-[5,4-d]thiazole covalent triazine polymer material includes the following steps:

[0007] 1) Mix thiazole-[5,4-d]thiazole monomers and anhydrous zinc chloride evenly and transfer them to a glass tube, cool with liquid nitrogen, and then melt and seal under vacuum;

[0008] 2) Transfer the sealed glass tube to a muffle furnace for heating and reaction to obtain the product;

[0009] 3) The product was taken out, ground, washed, and vacuum dried to obtain thiazole-[5,4-d]thiazole covalent triazine polymer material.

[0010] Preferably, the monomer in step 1) is prepared by the following method: mixing dithiooxazone and 4-formylbenzonitrile and heating to carry out a polycondensation reaction to obtain a thiazole-[5,4-d]thiazole monomer.

[0011] Preferably, the molar ratio of anhydrous zinc chloride to monomer in step 1) is 1 to 10.

[0012] Preferably, the liquid nitrogen cooling time in step 1) is 5 to 15 minutes.

[0013] Preferably, the heating rate in step 2) is 2 to 10 °C / min.

[0014] Preferably, the heating temperature in step 2) is 300-500℃ and the heating time is 24-72h.

[0015] Preferably, the grinding method used in step 3) is ball milling for 5-10 minutes.

[0016] Preferably, the solvents used for washing in step 3) are, in order, HCl aqueous solution, H2O, methanol, and acetone.

[0017] Preferably, the product in step 3) is dried at a temperature of 60-80°C and a drying time of 12-48 hours during vacuum drying.

[0018] The thiazole-[5,4-d]thiazole covalent triazine polymer material is prepared by the preparation method described above.

[0019] Applications of the thiazole-[5,4-d]thiazole covalent triazine polymer material include its use as a photothermal material for solar water evaporation.

[0020] The beneficial effects of this invention are: the thiazole-[5,4-d]thiazole covalent triazine polymer material of this invention has high photothermal conversion efficiency, simple synthesis, and good stability, making it suitable as a photothermal conversion material and showing great application prospects in the field of water evaporation. Specifically:

[0021] 1) This invention uses a high-temperature ionothermal method to prepare a black powder, which is a very promising photothermal conversion material with free radical properties and high stability.

[0022] 2) This invention directly utilizes monomer trimerization to generate the target product, which is simple and convenient to synthesize.

[0023] 3) The thiazole-[5,4-d]thiazole covalent triazine polymer material of the present invention has high photothermal conversion efficiency and can be used as a solar water evaporation material, with broad application prospects. Attached Figure Description

[0024] Figure 1 The infrared spectra of the monomer DTz-CN and the thiazole [5,4-d]thiazole covalent triazine polymer CTF-DTz in the examples are shown.

[0025] Figure 2 The powder X-ray diffraction patterns of DTz-CN and CTF-DTz in the examples are shown.

[0026] Figure 3 The thermogravimetrics of DTz-CN and CTF-DTz in the embodiments are shown.

[0027] Figure 4 The nitrogen adsorption-desorption isotherm of CTF-DTz in the example is shown.

[0028] Figure 5 The image shows the CTF-DTz UV-Vis absorption spectrum in the example.

[0029] Figure 6 The image shows the CTF-DTz electron paramagnetic resonance spectrum in the example.

[0030] Figure 7 The image shows the CTF-DTz temperature rise curve in the example.

[0031] Figure 8 The image shows the CTF-DTz water evaporation curve in the example. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0033] Example 1:

[0034] A thiazole-[5,4-d]thiazole covalent triazine polymer material, the preparation method of which includes the following steps:

[0035] Synthesis of monomer DTz-CN: Dithiooxazone (600.99 mg, 5 mmol) was added to a nitrobenzene suspension (100 mL) of 4-formylbenzonitrile (1.31 g, 10 mmol), and heated overnight at 130 °C. The resulting mixture was cooled to room temperature, and diethyl ether was added to form a red solid. The solid was filtered and washed with Et2O without further purification. Since this compound is insoluble in water, it could not be detected by NMR and HRMS.

[0036] The synthesis reaction formula for monomer DTz-CN is as follows:

[0037]

[0038] Synthesis of the thiazole-[5,4-d]thiazole covalent triazine polymer CTF-DTz: DTz-CN (344.4 mg, 1 mmol) and ZnCl2 (680 mg, 5.0 mmol, 5 eq) were uniformly mixed and transferred to a glass tube (1 × 14 cm). After cooling with liquid nitrogen for 5 min, the mixture was melt-sealed under vacuum. The sealed glass tube was then transferred to a muffle furnace for heating reaction at a temperature program of 5 °C / min, 400 °C, for 40 h. After the reaction, the mixture was cooled to room temperature. The cooled sample was removed, ground, and washed with 2 M HCl (5 × 100 mL), H2O (5 × 100 mL), methanol (3 × 50 mL), and acetone (1 × 50 mL). The washed sample was then dried in a vacuum drying oven at 60 °C for 12 h to obtain a dark powder.

[0039] The synthetic reaction formula for the thiazole-[5,4-d]thiazole covalent triazine polymer CTF-DTz is as follows:

[0040]

[0041] Performance testing:

[0042] 1) The infrared spectra of DTz-CN and CTF-DTz are as follows: Figure 1 As shown.

[0043] Depend on Figure 1 We know that: 2233cm -1 The disappearance of the nitrile bond and 1580 cm -1 The appearance of a strong absorption band indicates the formation of a triazine ring, suggesting that the nitrile group was successfully converted into a triazine structure through a trimerization reaction, i.e., the formation of CTF-DTz.

[0044] 2) Powder X-ray diffraction patterns of DTz-CN and CTF-DTz are as follows: Figure 2 As shown.

[0045] Depend on Figure 2 It can be seen that the diffraction peak of CTF-DTz formed after cyano trimerization is 25° at 2θ, which confirms the formation of the crystallization property of CTF-DTz.

[0046] 3) Thermogravimetric diagrams of DTz-CN and CTF-DTz are as follows: Figure 3 As shown.

[0047] Depend on Figure 3It can be seen that DTz-CTF retains 90% of its initial weight at 606℃ under a nitrogen atmosphere, indicating that it has high thermal stability.

[0048] 4) Nitrogen adsorption-desorption isotherms of CTF-DTz, such as Figure 4 As shown.

[0049] Depend on Figure 4 The adsorption isotherm of CTF-DTz exhibits typical Type I characteristics, with sharp N2 uptake in the low relative pressure region (P / P0 < 0.05), indicating microporous properties. The Brunol-Emmett-Teller (BET) surface area of ​​DTz-CTF is 1061.5 m². 2 / g. The gas adsorption curves of the samples before and after light irradiation basically overlap, indicating that the porosity remains essentially unchanged and the structural stability is very good.

[0050] 5) CTF-DTz UV-Vis absorption spectrum as shown in the figure. Figure 5 As shown.

[0051] Depend on Figure 5 It can be seen that CTF-DTz exhibits a strong and extended absorption spectrum in the range of 300–2500 nm. The broadening and strong absorption are likely due to the low band gap of the π-π conjugated structure and its spatial interactions.

[0052] 6) CTF-DTz electron spin resonance spectrum as shown Figure 6 As shown.

[0053] Depend on Figure 6 It can be seen that the CTF-DTz exhibits a significant ESR signal at G factor = 2.003, indicating the generation of carbon radicals. Temperature-dependent ESR measurements from 195 K to 275 K show that the peak height in CTF-DTz increases with increasing temperature, indicating increased spin parallelism, a characteristic of localized radicals with weak spin-spin interactions.

[0054] 7) The CTF-DTz temperature rise curve is as follows: Figure 7 As shown.

[0055] Depend on Figure 7 It can be seen that CTF-DTz heats up rapidly after being irradiated by a laser with a wavelength of 808nm, and the rate of temperature increase varies with the power of the laser lamp, reaching 0.8W / cm². 2 The sample was heated to 220°C under laser irradiation.

[0056] 8) CTF-DTz water evaporation curve as shown Figure 8 As shown.

[0057] Depend on Figure 8It can be seen that the mass of water in the beaker containing CTF-DTz decreased after 1 hour of light exposure. Calculations show that the water evaporation rate is 2.0 kg / m³. -2 h -1 The solar energy conversion efficiency is as high as 99.4%.

[0058] Example 2:

[0059] Unlike Example 1, in this example, 1 mmol of DTz-CN and 5.0 mmol of ZnCl2 were uniformly mixed, transferred to a glass tube, cooled with liquid nitrogen for 5 min, and then melt-sealed under vacuum. The sealed glass tube was transferred to a muffle furnace for heating reaction, with a temperature program of 5 °C / min, 400 °C, and 40 h. After the reaction, the mixture was cooled to room temperature. The cooled sample was removed, ground, and washed with 2M HCl (5 × 100 mL), H2O (5 × 100 mL), methanol (3 × 50 mL), and acetone (1 × 50 mL). The washed sample was then dried in a vacuum drying oven at 60 °C for 12 h to obtain a dark powder.

[0060] Example 3:

[0061] Unlike Examples 1 and 2, in this example, 1 mmol of DTz-CN and 10 mmol of ZnCl2 were uniformly mixed, transferred to a glass tube, cooled with liquid nitrogen for 15 min, and then melt-sealed under vacuum. The sealed glass tube was then transferred to a muffle furnace for heating reaction, with the following temperature program: 2 °C / min, 500 °C, 72 h. After the reaction, the mixture was cooled to room temperature. The cooled sample was removed, ground, and washed with 2M HCl (5 × 100 mL), H2O (5 × 100 mL), methanol (3 × 50 mL), and acetone (1 × 50 mL). The washed sample was then dried in a vacuum drying oven at 70 °C for 48 h to obtain a dark powder.

[0062] Example 4:

[0063] Unlike Examples 1-3, in this example, 1 mmol of DTz-CN and 8.0 mmol of ZnCl2 were uniformly mixed, transferred to a glass tube, cooled with liquid nitrogen for 8 min, and then melt-sealed under vacuum. The sealed glass tube was transferred to a muffle furnace for heating reaction, with a temperature program of 10 °C / min, 300 °C, for 24 h. After the reaction, the mixture was cooled to room temperature. The cooled sample was removed, ground, and washed with 2M HCl (5 × 100 mL), H2O (5 × 100 mL), methanol (3 × 50 mL), and acetone (1 × 50 mL). The washed sample was then dried in a vacuum drying oven at 80 °C for 24 h to obtain a dark powder.

[0064] Example 5:

[0065] Unlike Examples 1-4, in this example, 1 mmol of DTz-CN and 3.0 mmol of ZnCl2 were uniformly mixed, transferred to a glass tube, cooled with liquid nitrogen for 6 min, and then melt-sealed under vacuum. The sealed glass tube was transferred to a muffle furnace for heating reaction, with a temperature program of 8 °C / min, 350 °C, and 50 h. After the reaction, the mixture was cooled to room temperature. The cooled sample was removed, ground, and washed with 2M HCl (5 × 100 mL), H2O (5 × 100 mL), methanol (3 × 50 mL), and acetone (1 × 50 mL). The washed sample was then dried in a vacuum drying oven at 65 °C for 40 h to obtain a dark powder.

[0066] Example 6:

[0067] Unlike Examples 1-5, in this example, 1 mmol of DTz-CN and 2.0 mmol of ZnCl2 were uniformly mixed, transferred to a glass tube, cooled with liquid nitrogen for 10 min, and then melt-sealed under vacuum. The sealed glass tube was transferred to a muffle furnace for heating reaction, with a temperature program of 6 °C / min, 450 °C, and 60 h. After the reaction, the mixture was cooled to room temperature. The cooled sample was removed, ground, and washed with 2M HCl (5 × 100 mL), H2O (5 × 100 mL), methanol (3 × 50 mL), and acetone (1 × 50 mL). The washed sample was then dried in a vacuum drying oven at 75 °C for 30 h to obtain a dark powder.

[0068] The detection results of the thiazole-[5,4-d]thiazole covalent triazine polymer CTF-DTz obtained in Examples 2-6 above were the same as those in Example 1.

[0069] The above embodiments are merely for understanding the technical solution of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make various other corresponding changes and modifications based on the technical solution and concept of the present invention, and all such changes and modifications fall within the protection scope of the appended claims.

Claims

1. A method for preparing a thiazole-[5,4-d]thiazole covalent triazine polymer material, characterized in that, Includes the following steps: 1) The thiazole-[5,4-d]thiazole monomer and anhydrous zinc chloride were uniformly mixed and transferred into a glass tube. After cooling with liquid nitrogen, the mixture was melted and sealed under vacuum. 2) Transfer the sealed glass tube to a muffle furnace for heating and reaction to obtain the product; 3) The product was removed, ground, washed, and vacuum dried to obtain a thiazole-[5,4-d]thiazole covalent triazine polymer material; Step 1) The monomer is prepared by the following method: dithiooxazone and 4-formylbenzonitrile are mixed and heated to carry out a polycondensation reaction to obtain thiazole-[5,4-d]thiazole monomer; wherein the heating condition is 130°C, the resulting mixture is cooled to room temperature, diethyl ether is added to form a red solid, which is filtered and washed with Et2O without further purification; Step 2) The heating temperature is 300~500 ℃, the heating time is 24~72 h, and the heating rate is 2~10 ℃ / min.

2. The method for preparing a thiazole-[5,4-d]thiazole covalent triazine polymer material according to claim 1, characterized in that: Step 1) The molar ratio of anhydrous zinc chloride to monomer is 1~10.

3. The method for preparing a thiazole-[5,4-d]thiazole covalent triazine polymer material according to claim 1, characterized in that: Step 1) The liquid nitrogen cooling time is 5~15 min.

4. The method for preparing a thiazole-[5,4-d]thiazole covalent triazine polymer material according to claim 1, characterized in that: Step 3) The grinding method used is ball milling for 5-10 minutes.

5. The method for preparing a thiazole-[5,4-d]thiazole covalent triazine polymer material according to claim 1, characterized in that: Step 3) The washing solvents are, in order, HCl aqueous solution, H2O, methanol, and acetone.

6. The method for preparing a thiazole-[5,4-d]thiazole covalent triazine polymer material according to claim 1, characterized in that: Step 3) The product is dried at a temperature of 60~80 ℃ during the vacuum drying process, and the drying time is 12~48h.

7. A thiazole-[5,4-d]thiazole covalent triazine polymer material, characterized in that: The thiazole-[5,4-d]thiazole covalent triazine polymer material is prepared by the method described in any one of claims 1-6.

8. The application of the thiazole-[5,4-d]thiazole covalent triazine polymer material of claim 7 in solar water evaporation during photothermal conversion.

Images