Preparation method of nano mesoporous material
By dissolving lauryl betaine and betaine at room temperature, and adding TEOS and aniline methyltriethoxysilane dropwise, silica nanomesoporous materials with high specific surface area and suitable mesoporous size are prepared, which solves the problem of high cost of template agents and difficult to control material characteristics in traditional methods, and achieves the effect of simplifying the process and reducing costs.
Patent Information
- Application Number
- CN202411871780.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-18
- Publication Date
- 2025-06-27
AI Technical Summary
Traditional mesoporous material preparation methods have problems such as high cost of template agents, complex post-processing, difficulty in achieving large-scale industrial production, and difficulty in controlling the composition, crystal form and particle size of the material at the same time.
By dissolving lauryl betaine and betaine at room temperature, stirring with ammonia water, then adding TEOS and aniline methyltriethoxysilane dropwise, stirring and calcining, obtaining silica nanomesoporous material with high specific surface area and moderate mesoporous size.
Spherical mesoporous silica particles with specific surface area of 800 to 1200 m2/g, mesoporous size of 2.0 to 3.5 nm and particle size of 100 to 600 nm were prepared, which simplifies the process flow, reduces costs, and is suitable for large-scale industrial applications.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of porous materials, and in particular to a method for preparing a nano-mesoporous material. Background Art
[0002] Mesoporous materials are a new type of nanostructured materials that emerged rapidly in the 1990s. As soon as they were born, they were highly valued by researchers in the fields of chemistry, materials science and physics, and quickly developed into an interdisciplinary research hotspot. The International Union of Pure and Applied Chemistry (IUPAC) stipulates that porous solid materials can be divided into three categories: microporous solids (pore size less than 2nm), mesoporous solids (pore size between 2-50nm), and macroporous solids (pore size greater than 50nm). Among them, mesoporous materials are a new type of material with a pore size between micropores and macropores, a large specific surface area and a three-dimensional pore structure. Its research and development is of great significance for both theoretical research and practical production.
[0003] As an important type of mesoporous material, mesoporous oxides have many excellent properties: uniform pore size distribution, and the pore size can vary in a wide range; the mesopore shape is diverse, and the pore wall composition and properties are adjustable; high thermal stability and hydrothermal stability can be obtained by optimizing the synthesis conditions; it has a very high specific surface area and porosity, so it has potential application prospects in many fields such as catalysis, adsorption, separation, light, electricity, and magnetism. For example: mesoporous silica, alumina and other materials have large pore size, high specific surface and large pore volume, and are excellent catalyst carrier materials. Their large-size pores provide a good reaction site for the catalytic reaction of large-size molecules. Their good modifiability provides the possibility of immobilization for many catalysts, and their high specific surface area brings a significant improvement in the catalytic performance of many intrinsic catalyst materials. As another important mesoporous material, mesoporous metal materials have the advantages of large specific surface area, strong light absorption ability, and good thermal conductivity at low temperature. In particular, mesoporous metals have shown attractive application prospects in the fields of selective adsorption and separation, catalysts, optoelectronic devices, electrode materials and sensors due to their special pore structure, quantum effect and interface coupling effect. Mesoporous metals have more far-reaching practical application value in the field of catalysis. Their pore size is just within the molecular size and can be used as molecular "microreactors". At the same time, due to their rich topological structure and large specific surface area, they can better control the selectivity and activity of the reaction and are expected to be used in chiral synthesis.
[0004] At present, the synthesis methods of mesoporous materials can be roughly divided into two categories: soft template method and hard template method. The soft template method mainly refers to using surfactants or amphiphilic polymers as template agents, and utilizing the interfacial assembly force between the organic phase and inorganic species in the solution to synthesize mesoporous materials through nano self-assembly technology. The main process of the hard template method is to use the pores of preformed mesoporous solids and impregnate them internally to obtain inverse mesoporous structure materials with the required components. During the synthesis process of the hard template method, metal precursors need to enter the pores of the mesoporous template, so there may be a problem of low pore occupancy of the precursors, which will lead to poor continuity of the synthesized mesoporous materials. In addition, using the formed mesoporous materials as template agents has a high cost, and the removal of the template agent is also a relatively cumbersome process, which limits the large-scale industrial application of this method.
[0005] All in all, due to the high cost of template agents, complex post-treatment, and high cost, the traditional preparation methods of mesoporous materials are difficult to achieve large-scale industrial production. Moreover, it is difficult to simultaneously control the components, crystal forms, and particle sizes of mesoporous materials. In addition, due to various limitations, traditional synthesis methods cannot be widely used in the preparation of various mesoporous metal oxides and metal materials. Therefore, it is crucial to propose a simple, low-cost, and widely applicable preparation method for nano mesoporous materials, and at the same time, be able to control the composition, crystal phase, and size of the materials during the synthesis process for the large-scale application of mesoporous materials. Summary of the Invention
[0006] In view of the above technical problems, the present invention provides a preparation method for nano mesoporous materials.
[0007] Technical Solution: A preparation method for nano mesoporous materials, comprising the following steps: S1: Dissolve lauryl betaine and betaine in deionized water at room temperature in a certain proportion, add ammonia water and stir for 20 - 40 min; S2: Dropwise add TEOS (tetraethyl orthosilicate) and anilinomethyltriethoxysilane, and continue stirring for 4 - 5 h; S3: After the reactants are centrifuged, washed, dried, and calcined, silica nano mesoporous materials are obtained.
[0008] Further, in S1, the molar ratio of lauryl betaine to betaine is 2 - 5:1 - 2, and the total concentration of the mixed solution is 0.01 - 5 mol / L.
[0009] Preferably, in S1, the molar ratio of lauryl betaine to betaine is 2 - 5:1.
[0010] Further, the concentration of the ammonia water is 25% - 28%, and the volume ratio of the ammonia water added in S1 to water is 1 - 1.5:100.
[0011] Further, the volume ratio of TEOS added in S2 to water in S1 is 3 - 10:100.
[0012] Further, the volume ratio of anilinomethyltriethoxysilane added in S2 to water in S1 is 0.1 - 0.3:100.
[0013] Further, the temperature of the stirring reaction in S2 is 30 - 60 °C.
[0014] Further, in S3, it is washed three times with water and ethanol respectively, dried at 60 - 100 °C for 10 - 24 h after washing, and calcined at 650 - 800 °C for 8 - 10 h after drying.
[0015] Beneficial effects: By adjusting the ratio of two surfactants with different molecular weights, lauryl betaine and betaine, in the present invention, lauryl betaine causes the colloidal silica particles to coagulate and precipitate, betaine plays a role in controlling the rejection of alternating silica particles, and anilinomethyltriethoxysilane plays a role in controlling the morphology of mesoporous silica, thereby obtaining spherical mesoporous silica particles with a specific surface area of 800 - 1200 m 2 / g and a mesopore size of 2.0 - 3.5 nm; and the particle size is between 100 - 600 nm. Specific embodiments
[0016] The present invention will be specifically described below.
[0017] Example 1: A preparation method of a nano - mesoporous material, comprising the following steps: S1: At room temperature, lauryl betaine and betaine are dissolved in deionized water according to a molar ratio of 2 - 5:1 - 2, the total concentration of the mixed solution is 0.01 - 5 mol / L, ammonia water with a concentration of 25% - 28% is added and stirred for 20 - 40 min, and the volume ratio of ammonia water to water is 1 - 1.5:100; S2: TEOS (tetraethyl orthosilicate) and anilinomethyltriethoxysilane are added dropwise, and stirring is continued at 30 - 60 °C for 4 - 5 h; the volume ratio of TEOS to water in S1 is 3 - 10:100; the volume ratio of anilinomethyltriethoxysilane to water in S1 is 0.1 - 0.3:100; S3: The reactants are centrifuged, washed three times with water and ethanol respectively, dried at 60 - 100 °C for 10 - 24 h, and calcined at 650 - 800 °C for 8 - 10 h to obtain a silica nano - mesoporous material.
[0018] Select initial raw materials in different proportions and carry out reactions according to the above steps to prepare silica nano-mesoporous materials, where the reaction temperature of S2 is 30 °C and the calcination temperature of S3 is 700 °C. The specific raw material proportions and the average particle size range and pore size data of the prepared silica nano-mesoporous materials are shown in Table 1: Table 1: Using the above initial raw materials in different proportions as reactants, the final reaction yields a specific surface area of 800 - 1200 m 2 / g, mesopore size of 2.0 - 3.5 nm; spherical mesoporous silica particles with a particle size between 100 - 600 nm. As can be seen from Table 1, by adjusting the proportion of two surfactants with different molecular weights, lauryl betaine and betaine, the average particle size range of the spherical mesoporous silica particles can be changed.
[0019] Example 2: Prepare silica nano-mesoporous materials using the same preparation method as in Example 1, and select initial raw materials in different proportions. The specific raw material proportions and the average particle size range and pore size data of the prepared silica nano-mesoporous materials are shown in Table 2.
[0020] Table 2: As can be seen from Table 2, controlling the addition amount of anilinomethyltriethoxysilane can adjust the average particle size range and pore size of the prepared silica nano-mesoporous materials to a certain extent. As the amount of anilinomethyltriethoxysilane increases, the average particle size range continuously increases and the pore size continuously decreases.
[0021] Example 3: Prepare silica nano-mesoporous materials using the same method as in Example 1. The proportion of the initial raw materials is the same as that of No. 5 in Table 1 of Example 1. The reaction temperature of S2 is increased from 30 °C to 60 °C, and other reaction conditions remain unchanged. The average particle size range of the prepared silica nano-mesoporous materials is 350 - 450 nm, and the pore size of 2.5 nm remains unchanged. The temperature has no obvious effect on the reaction.
[0022] 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 protection scope of the claims of this application.
Claims
1. A method for preparing a nano-mesoporous material, characterized in that: The following steps are involved: S1: Dissolve lauryl betaine and betaine in deionized water at a certain ratio at room temperature, add ammonia water and stir for 20-40 minutes; S2: Add TEOS (ethyl orthosilicate) and aniline methyl triethoxysilane dropwise and continue stirring for 4-5 hours; S3: The reactants are centrifuged, washed, dried and calcined to obtain silica nano-mesoporous material.
2. The method for preparing a nano-mesoporous material according to claim 1, characterized in that: The molar ratio of lauryl betaine to betaine in S1 is 2-5:1-2, and the total concentration of the mixed solution is 0.01-5 mol / L.
3. The method for preparing a nano-mesoporous material according to claim 1, characterized in that: The molar ratio of lauryl betaine to betaine in S1 is 2-5:
1.
4. The method for preparing a nano-mesoporous material according to claim 2, characterized in that: The concentration of the ammonia water is 25%-28%, and the volume ratio of the ammonia water to water added in S1 is 1-1.5:
100.
5. The method for preparing a nano-mesoporous material according to claim 3, characterized in that: The volume ratio of TEOS added in S2 to water in S1 is 3-10:
100.
6. The method for preparing a nano-mesoporous material according to claim 4, characterized in that: The volume ratio of anilinemethyltriethoxysilane added in S2 to water in S1 is 0.1-0.3:
100.
7. A method for preparing a nano-mesoporous material according to any one of claims 1 to 6, characterized in that: The temperature of the stirring reaction in S2 is 30-60°C.
8. The method for preparing a nano-mesoporous material according to claim 7, characterized in that: In S3, the washing is performed three times with water and ethanol respectively, and then dried at 60-100° C. for 10-24 h, and then calcined at 650-800° C. for 8-10 h.