Preparation method of organic-inorganic composite functional mesoporous material

Abstract

The invention discloses a preparation method of an organic-inorganic composite functional mesoporous material, which comprises the following steps: S1, preparing an organic silicon precursor: dissolving a reactant A1 and IPTES in DMSO, then adding TEDA (triethylene diamine) into the solution, refluxing for 45-55 hours at the temperature of 100-110 DEG C in a nitrogen atmosphere, and obtaining the organic silicon precursor A1-Si after the reaction is finished; s2, adding CTAB (cetyltrimethylammonium bromide) as a template agent into the DES solvent, continuing to stir, adding an organic silicon precursor A1-Si and TEOS (tetraethyl orthosilicate) as a mixed silicon source into the solution, heating and stirring for 2-3 hours, adding a sodium hydroxide solution to adjust the pH to 10, stopping heating, transferring the solution into a high-pressure kettle, reacting in a drying oven at 110-130 DEG C for 10-15 hours, and cooling to room temperature, so as to obtain the organic silicon composite material. And performing post-treatment to obtain a solid, namely the organic-inorganic composite functional mesoporous material. According to the preparation method of the organic-inorganic composite functional mesoporous material provided by the invention, the synthesized mesoporous material does not have the problem of pore blockage, and organic groups are more uniformly distributed on pore walls.

Description

Technical Field

[0001] The present invention relates to the technical field of nanomaterials, and particularly to a preparation method of an organic-inorganic composite functional mesoporous material. Background Art

[0002] Mesoporous polymer materials have excellent properties such as high stability, easy modifiability, high specific surface area, and large pore volume, and have extensive applications in many fields such as catalyst carriers, gas adsorbents, gas storage materials, and electrode materials, and even have important applications in the biomedical field.

[0003] Porous materials can be classified into the following three types according to the pore diameter: micropores with a pore diameter of less than 2 nm; mesopores with a pore diameter between 2 and 50 nm; and macropores with a pore diameter of more than 50 nm. Ordered mesoporous materials have the following characteristics: (1) regular and ordered pore structures; (2) adjustable pore diameters; (3) relatively large specific surface areas, etc. Due to the inactive chemical properties of inorganic mesoporous silica, its applications are limited. Scientists have gradually introduced organic groups into mesoporous silica through covalent bonds. The organic groups provide new active sites, while the silica skeleton provides a rigid physical environment, making the chemical properties of the material more stable. This organic-inorganic hybrid mesoporous material simultaneously has the active chemical properties of organic groups and the stability of inorganic groups, and thus has extensive applications in various fields such as sensing and adsorption.

[0004] There are mainly three methods for introducing organic groups into inorganic mesoporous materials: the first is the direct modification of the pore surface of pure inorganic silica materials (post-grafting method); the second is the simultaneous condensation of silica and organosiloxane precursors (co-condensation); the third is the use of bis-silylated organosilicon precursors to introduce organic groups as bridging components into the pore walls (bridging bond type).

[0005] The present invention provides a mesoporous material hybridized with an organic group having a terpyridine structure and silica to expand the application fields of mesoporous materials. Summary of the Invention

[0006] In view of the above technical problems, the present invention provides a preparation method of an organic-inorganic composite functional mesoporous material.

[0007] Technical Solution: A preparation method of an organic-inorganic composite functional mesoporous material includes the following steps: S1. Prepare an organosilicon precursor, and the synthesis route is as follows: Dissolve reactant A1 and IPTES in DMSO, then add TEDA (triethylenediamine) to the solution, reflux at 100 - 110 °C for 45 - 55 h under a nitrogen atmosphere. After the reaction is completed, cool to room temperature. After removing the solvent, wash the obtained solid with n-hexane to obtain the organosilicon precursor A1-Si; S2: Add choline chloride (ChCl) and urea to ethylene glycol, heat and stir until a homogeneous and transparent DES solvent is formed, continue stirring for 30 min to stabilize DES. Add CTAB (cetyltrimethylammonium bromide) as a template agent to the DES solvent and continue stirring. Add the organosilicon precursor A1-Si and TEOS (tetraethyl orthosilicate) as a mixed silicon source to the solution, heat and stir for 2 - 3 h, then add sodium hydroxide solution to adjust the pH to 10, turn off the heating, transfer the solution to an autoclave, and react at 110 - 130 °C in an oven for 10 - 15 h. After post-treatment, the obtained solid is the organic-inorganic composite functional mesoporous material.

[0008] Furthermore, in S1, the molar ratio of reactant A1 to IPTES is 1:2 - 3, and the molar ratio of reactant A1 to TEDA is 1:0.3 - 0.5.

[0009] Furthermore, the reaction temperature in S1 is 105 °C and the reaction time is 50 h.

[0010] Furthermore, in S2, the molar ratio of choline chloride, urea and ethylene glycol is 1:2:2, and the molar ratio of CTAB to choline chloride is 1 - 3:5.

[0011] Furthermore, in S2, the molar ratio of TEOS to choline chloride is 0.7 - 1:1, and the mass of the organosilicon precursor A1-Si is 2 - 10% of the total mass of the mixed silicon source.

[0012] Furthermore, the post-treatment steps in S2 include cooling to room temperature, filtering the product, washing the product with ethanol and water multiple times, and using ethanol as an extractant to remove the residual CTAB in the solid by Soxhlet extraction.

[0013] Furthermore, the reactant A1 is synthesized through the following route: It includes the following steps: Dissolve 3,5-dimethylbenzaldehyde in absolute ethanol, then add 2 - 3 times the molar amount of potassium hydroxide. After complete dissolution, add 2-acetylpyridine, react at 60 °C with stirring for 10 - 12 h, then add ammonia water and reflux for 60 - 80 h. Filter to obtain a solid, wash the solid with ethanol, and dry to obtain an intermediate; reflux the intermediate with HBr to remove the methyl group, remove most of the HBr by vacuum distillation, adjust the pH with sodium bicarbonate, and purify by column chromatography to obtain the reactant A1.

[0014] Beneficial effects: The present invention provides a method for preparing an organic-inorganic composite functional mesoporous material. By reacting a reactant A1 with a terpyridine structure and IPTES, an organosilicon precursor is prepared. Under the action of a template agent, the organosilicon precursor and TEOS are used as a mixed silicon source for co-condensation to obtain a mesoporous silica material. The synthesized mesoporous material has no problem of pore blockage, and the organic groups are more evenly distributed on the pore walls. The synthesized material has a strong coordination effect on Fe 3+ 、Co 2+ 、Cu 2+ and Zn 2+ and can be applied to the field of sensors. Specific embodiments

[0015] The present invention will be specifically described below.

[0016] Example 1: Prepare reactant A1, and the reaction route is as follows: It includes the following steps: Add 3,5-dimethylbenzaldehyde (3.32 g, 20 mmol) to anhydrous ethanol for dissolution, then add 3.4 g of potassium hydroxide. After complete dissolution, add 2-acetylpyridine (4.85 g, 40 mmol), react at 60 °C for 12 h with stirring, then add 50 mL of ammonia water and reflux for 70 h, filter to obtain a solid, wash the solid with ethanol, and dry to obtain an intermediate; the intermediate is refluxed with HBr to remove the methyl group, after most of the HBr is removed by distillation under reduced pressure, adjust the pH with sodium bicarbonate, and purify by column chromatography (ethyl acetate: petroleum ether = 1:2) to obtain 1.55 g of the reactant A1.

[0017] Example 2: Prepare an organosilicon precursor, and the synthesis route is as follows: Dissolve reactant A1 (0.37 g, 1 mmol) and IPTES (0.75 g, 3 mmol) in DMSO (100 mL), then add TEDA (0.045 g, 0.4 mmol) to the solution, reflux at 105 °C for 50 h under a nitrogen atmosphere. After the reaction is completed, cool to room temperature. After removing the solvent, the obtained solid is washed with n-hexane to obtain the organosilicon precursor A1-Si (0.54 g, yield 68%); S2: Add choline chloride (3.5 g, 25 mmol) and urea (3 g, 50 mmol) into ethylene glycol (2.8 mL, 50 mmol), heat and stir until a homogeneous and transparent DES solvent is formed. Continue stirring for 30 min to stabilize the DES. Add cetyltrimethylammonium bromide (CTAB) (4 g, 11 mmol) as a templating agent into the DES solvent and continue stirring. Add the mixed silicon sources of organosilicon precursor A1-Si and TEOS (5 mL, 22 mmol) into the solution, with the proportion of organosilicon precursor A1-Si being 2 - 10%. After heating and stirring for 2.5 h, add 40% sodium hydroxide solution to adjust the pH to 10. Turn off the heating, transfer the solution to an autoclave, and react at 120 °C in an oven for 12 h. Cool to room temperature, filter the product, wash the product with ethanol and water multiple times. Use ethanol as an extractant to remove the residual CTAB in the solid by Soxhlet extraction. Finally, the obtained solid is the organic-inorganic composite functional mesoporous material.

[0018] Test Example 1: Disperse the organic-inorganic composite functional mesoporous material in water to prepare a suspension of 1 mg / mL, add an excessive amount of aqueous solutions containing different metal ions, including K + , Ca 2+ , Na + , Mg 2+ , Al 3+ , Cr 3+ , Fe 3+ , Cu 2+ , Zn 2+ , Cd 2+ , Pb 2+ , Co 2+ . Record its luminescence properties under a 365 nm ultraviolet analyzer. Among them, when adding Fe 3+ , Co 2+ , Cu 2+ and Zn 2+ , the fluorescence intensity and luminescence color change significantly. When the proportion of organosilicon precursor A1-Si is 5 - 10%, the color change is more significant, indicating that the organic-inorganic composite functional mesoporous material has a strong coordination effect on Fe 3+ , Co 2+ , Cu 2+ and Zn 2+ , has a sensing ability and can be applied to the field of sensor technology.

[0019] Although the present invention has been disclosed above with preferred embodiments, they are not used to limit the present invention. Any person skilled in this art can make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be defined by the scope of the claims of this application.

Claims

1. A preparation method of an organic-inorganic composite functional mesoporous material, characterized in that It includes the following steps: S1. Prepare an organosilicon precursor, and the synthesis route is as follows: Dissolve reactant A1 and IPTES in DMSO, then add TEDA (triethylenediamine) to the solution, reflux at 100 - 110 °C for 45 - 55 h under a nitrogen atmosphere. After the reaction is completed, cool to room temperature. The solid obtained after removing the solvent is washed with n-hexane to obtain the organosilicon precursor A1-Si; S2: Add choline chloride (ChCl) and urea to ethylene glycol, heat and stir until a homogeneous and transparent DES solvent is formed, continue to stir for 30 min to stabilize DES. Add CTAB (cetyltrimethylammonium bromide) as a template agent to the DES solvent and continue to stir. Use organosilicon precursor A1-Si and TEOS (tetraethyl orthosilicate) as a mixed silicon source and add them to the solution. After heating and stirring for 2 - 3 h, add sodium hydroxide solution to adjust the pH to 10, turn off the heating, transfer the solution to an autoclave, and react at 110 - 130 °C in an oven for 10 - 15 h. Post-treatment gives a solid which is the organic-inorganic composite functional mesoporous material.

2. The preparation method of an organic-inorganic composite functional mesoporous material according to claim 1, characterized in that, In S1, the molar ratio of reactant A1 to IPTES is 1:2 - 3, and the molar ratio of reactant A1 to TEDA is 1:0.3 - 0.

5.

3. The preparation method of an organic-inorganic composite functional mesoporous material according to claim 2, characterized in that, The reaction temperature in S1 is 105 °C and the reaction time is 50 h.

4. The preparation method of an organic-inorganic composite functional mesoporous material according to any one of claims 1-3, characterized in that, In S2, the molar ratio of choline chloride, urea and ethylene glycol is 1:2:2, and the molar ratio of CTAB to choline chloride is 1 - 3:

5.

5. The preparation method of an organic-inorganic composite functional mesoporous material according to claim 4, characterized in that, In S2, the molar ratio of TEOS to choline chloride is 0.7 - 1:1, and the mass of the organosilicon precursor A1-Si is 2 - 10% of the total mass of the mixed silicon source.

6. The preparation method of an organic-inorganic composite functional mesoporous material according to claim 5, characterized in that, The post-treatment steps in S2 include cooling to room temperature, filtering the product, washing the product with ethanol and water multiple times, and using ethanol as an extractant to remove the residual CTAB in the solid by Soxhlet extraction.

7. The preparation method of an organic-inorganic composite functional mesoporous material according to claim 1 or 5, characterized in that, The reactant A1 is synthesized through the following route: It includes the following steps: Dissolve 3,5-dimethylbenzaldehyde in absolute ethanol, then add 2 - 3 times the molar amount of potassium hydroxide. After complete dissolution, add 2-acetylpyridine, react at 60 °C with stirring for 10 - 12 h, then add ammonia water and reflux for 60 - 80 h. Filter to obtain a solid, wash the solid with ethanol, and dry to obtain an intermediate; reflux the intermediate with HBr to remove the methyl group, distill off most of the HBr under reduced pressure, adjust the pH with sodium bicarbonate, and purify by column chromatography to obtain the reactant A1.

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