Functionalized ordered mesoporous organosilicon microspheres with Yolk-Shell structure and preparation method thereof

Abstract

The present invention discloses a functionalized ordered mesoporous organosilicon microsphere with a Yolk-Shell structure and a preparation method thereof. The preparation steps include: (1) using functionalized nanoparticles as cores, utilizing a sol-gel chemical synthesis method, and wrapping a layer of amorphous silica on the surface of the functionalized nanoparticles through a hydrolysis and condensation process of a silicon source precursor at room temperature to obtain functionalized core-shell particles; (2) using the functionalized core-shell particles as seeds, dispersing them in a mixed solution containing deionized water, ethanol, ammonia water and a surfactant, adding organosilane to react, and obtaining functionalized ordered mesoporous organosilicon microspheres with a Yolk-Shell structure. Compared with the "post-etching method" preparation technology, the "quasi-one-step method" of the present invention has mild reaction conditions, simpler and more efficient preparation steps; in addition, by adopting different functionalized cores, Yolk-Shell mesoporous microspheres with different functions can be obtained, which has good universality.

Description

Technical Field

[0001] The present invention relates to the technical field of nanomaterials, and in particular to functionalized ordered mesoporous organosilicon microspheres with a Yolk-Shell structure and a preparation method thereof. Background Art

[0002] The rational design and controlled synthesis of hollow mesoporous materials has always been a challenging and significant research topic. Yolk-Shell mesoporous particles, which contain functional particles within their cavities, not only possess the inherent excellent properties of mesoporous materials, such as low density, high surface area, flexible modifiability, and good adsorption capacity, but also utilize the unique functionality of their cores, making them extremely promising for applications in sensing, adsorption, and catalysis.

[0003] Yolk-Shell mesoporous silica particles are prepared primarily by template-free and template-assisted methods. The hydrothermal method, also known as the self-templating method, is a typical template-free method. It forms a cavity structure through vapor expansion during solvent evaporation. However, the hydrothermal method's application is limited due to its poor controllability.

[0004] Template-assisted synthesis is a simple strategy for utilizing heterogeneous templates to modulate hollow Yolk-Shell mesoporous silica. In a typical Yolk-Shell mesoporous silica template synthesis, four steps are typically required: functional core preparation, template coating, mesoporous shell formation, and template removal. After template removal, the regions previously belonging to the template become hollow structures, forming so-called Yolk-Shell particles. This method offers the advantage of highly controllable structural parameters of the product.

[0005] It is not difficult to find that the template plays a decisive role in controlling the shape and cavity volume of hollow mesoporous silica. At present, there are many types of templates to choose from, and the methods for removing templates of different materials are also different. For example, carbon materials can be removed by high-temperature calcination; templates of polymer materials such as polystyrene, in addition to high-temperature calcination, can also be dissolved and removed using appropriate organic solvents (toluene, tetrahydrofuran, etc.); amorphous silica can often be dissolved in alkaline solutions or aqueous hydrogen fluoride solutions. However, the process of removing the template agent often inevitably affects the structure and morphology of Yolk-Shell type mesoporous silica particles. For example, the mesoporous silica shell is also partially dissolved, causing the Yolk-Shell particles to be damaged and even the cavity structure to be destroyed. The high-temperature calcination process will also remove some important organic functional groups. In addition, after obtaining the Yolk-Shell particles, the particles often need to be further modified and optimized. This process often has a negative impact on the morphological structure and particle dispersibility of the Yolk-Shell particles. In summary, it is very important to optimize and simplify the preparation method of Yolk-Shell mesoporous silica particles.

[0006] So far, many research groups have used PS as a template to prepare hollow silica particles. E. Bourgeat-Lami and his colleagues first synthesized PS latex particles modified with silanol groups, and then co-condensed the silanol groups with tetraethoxysilane to form composite particles with PS as the core and silica as the shell. The polystyrene core was thermally degraded to obtain hollow silica spheres. So far, a lot of effort has been made to develop flexible and universal coating routes to achieve precise control of the hollow structural parameters. However, there are few reports focusing on the synthesis of hollow mesoporous silica, especially mesoporous silica composed of mesoporous organic silica with vertically ordered channels and multifunctional magnetic components. Therefore, it is of great significance to develop a method for preparing multifunctional hollow periodic mesoporous organosilicon (HPMO) with large pores and large morphology. Summary of the Invention

[0007] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a functionalized ordered mesoporous organosilicon microsphere with a Yolk-Shell structure and a preparation method thereof. Compared with the "post-etching method" preparation technology, the "quasi-one-step method" of the present invention has mild reaction conditions and simpler and more efficient preparation steps. By adopting different functionalized cores, Yolk-Shell mesoporous microspheres with different functions can be obtained, which has good universality.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A functionalized ordered mesoporous organosilicon microsphere with a Yolk-Shell structure, comprising an inner core and a shell coating the outer core, with a gap between the inner core and the shell. The inner core is a functionalized nanoparticle with good dispersibility and stability in alkaline solution, and the shell is an ordered mesoporous organosilicon shell.

[0010] The functionalized nanoparticles are selected from metal nanoparticles and metal oxide nanocrystals; the particle size of the functionalized nanoparticles is 40 to 400 nm.

[0011] The metal nanoparticles are silver nanoparticles; the metal oxide nanocrystals are selected from one of ferroferric oxide nanocrystals and cobalt oxide nanocrystals; and the particle size of the functionalized nanoparticles is 30 to 155 nm.

[0012] The mesopore diameter of the ordered mesoporous organic silicon shell layer is 2-4 nm, and the thickness of the ordered mesoporous organic silicon shell layer is 40-200 nm.

[0013] The mesopore diameter of the ordered mesoporous organic silicon shell layer is 2.43-2.52 nm, and the thickness of the ordered mesoporous organic silicon shell layer is 18-50 nm.

[0014] Functionalized ordered mesoporous organosilicon microspheres with a Yolk-Shell structure are prepared by the following steps:

[0015] S1. Using functionalized nanoparticles as cores, a layer of amorphous silica is coated on the surface of the functionalized nanoparticles through the hydrolysis and polycondensation of silicon source precursors at room temperature to obtain functionalized core-shell particles.

[0016] S2. The functionalized core-shell particles are used as seeds and dispersed in a mixture of deionized water, ethanol, ammonia water and a surfactant. After being uniformly dispersed by stirring, organosilane is added and the reaction is continued by stirring to obtain functionalized ordered mesoporous organosilica microspheres with a Yolk-Shell structure.

[0017] The specific preparation steps of the functionalized core-shell particles in step S1 are as follows: the functionalized nanoparticles are uniformly dispersed in an alkaline mixture containing ethanol, deionized water, and an alkaline substance, a silicon source precursor is added, and the mixture is continuously stirred in a water bath at room temperature for 12 hours to obtain functionalized core-shell particles; the silicon source precursor is selected from one or more of ethyl orthosilicate, methyl orthosilicate, sodium silicate, or silicon tetrachloride.

[0018] In step S1, the ratio of the amount of functionalized nanoparticles to ethanol, deionized water, alkaline substance, and silicon source precursor is (50-100) mg:80 ml:20 ml:2 ml:(50-150) μL, the alkaline substance is ammonia water with a concentration of 5.0-8.0 mol / mL; the silicon source precursor is ethyl orthosilicate; the thickness of the amorphous silica shell in the functionalized core-shell particles is 5-100 nm; further, the thickness of the amorphous silica shell is 5-35 nm.

[0019] In step S2, the reaction solution obtained after the reaction is subjected to magnetic separation and washed with water and alcohol to obtain a solid product, which is then dried to obtain functionalized ordered mesoporous organosilicon microspheres with a Yolk-Shell structure;

[0020] In step S2, the surfactant is one or more of the alkyl quaternary ammonium salt surfactants; the organosilane is selected from at least one of 1,2-bis(triethoxysilyl)ethane, 1,2-bis(trimethoxysilyl)ethane, and bis-[γ-(triethoxysilyl)propyl]-tetrasulfide, or a mixture of at least one of 1,2-bis(triethoxysilyl)ethane, 1,2-bis(trimethoxysilyl)ethane, and bis-[γ-(triethoxysilyl)propyl]-tetrasulfide and ethyl orthosilicate.

[0021] The amount ratio of deionized water, ethanol, ammonia water, surfactant, organosilane in step S2 to the functionalized nanoparticles in step S1 is 90.0 mL: 30.0 mL: 1.2 mL: 165 mg: (100-250) μL: (50-100) mg, the concentration of ammonia water is 5.0-8.0 mol / mL, the surfactant is hexadecyltrimethylammonium bromide; the organosilane is 1,2-bis(triethoxysilyl)ethane or 1,2-bis(trimethoxysilyl)ethane; and the reaction temperature in step S2 is 25-35°C.

[0022] The beneficial effect of the present invention is that the method uses functionalized nanoparticles with amorphous silicon oxide coated on the surface as the core. In this system, the hydrolysis and polycondensation of organosilanes forms an ordered mesoporous organosilicon shell layer, while simultaneously dissolving the amorphous silicon oxide on the surface of the functionalized nanoparticles to obtain a cavity structure. Ultimately, functionalized ordered mesoporous organosilicon microspheres with a Yolk-Shell structure are obtained in one step. Compared with the traditional four-step template-assisted method, this method does not require an additional step to remove the template and has the advantages of simple and convenient steps, strong experimental reproducibility, and high preparation efficiency. The resulting Yolk-Shell type ordered mesoporous organosilicon microspheres have a particle size of 40 to 400 nm, a mesopore diameter of 2 to 4 nm, and a mesoporous shell thickness of 18 to 50 nm. They have great potential application value in sensing, adsorption, catalysis, and other aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 TEM image of Yolk-Shell type Fe3O4@viod@PMO microspheres prepared in Example 1;

[0024] Figure 2 TEM image of the Core-Dual Shell Fe3O4@SiO2@mSiO2 microspheres prepared in Comparative Example 1.

[0025] Figure 3 TEM image of Yolk-Shell type Fe3O4@viod@PMO microspheres prepared in Example 2;

[0026] Figure 4 TEM image of Yolk-Shell type Fe3O4@viod@PMO microspheres prepared in Example 3;

[0027] Figure 5 TEM image of Yolk-Shell type Fe3O4@viod@PMO microspheres prepared in Example 4;

[0028] Figure 6 TEM image of Yolk-Shell type Fe3O4@viod@PMO microspheres prepared in Example 5;

[0029] Figure 7 TEM image of Yolk-Shell type Co3O4@viod@PMO microspheres prepared in Example 6;

[0030] Figure 8 TEM image of Yolk-Shell type Ag@viod@PMO microspheres prepared in Example 7;

[0031] Figure 9 is the N2 adsorption-desorption curve of the sample in Example 1;

[0032] Figure 10 The infrared comparison spectra of the microspheres prepared in Example 1 and Comparative Example 1 are shown. DETAILED DESCRIPTION

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0034] The preparation steps of functionalized ordered mesoporous organosilicon microspheres with Yolk-Shell structure are as follows:

[0035] S1. Using functionalized nanoparticles as the core, a sol-gel chemical synthesis method is used to wrap a layer of amorphous silica on the surface of the functionalized nanoparticles through the hydrolysis and condensation process of the silicon source precursor at room temperature to obtain functionalized core-shell particles; specifically, the functionalized nanoparticles are uniformly dispersed in an alkaline mixture containing ethanol, deionized water, and alkaline substances, the silicon source precursor is added, and the mixture is continuously stirred in a water bath at room temperature for 12 hours to obtain functionalized core-shell particles.

[0036] In this step, the silicon source precursor is selected from one or more of ethyl orthosilicate, methyl orthosilicate, sodium silicate or silicon tetrachloride, and the hydrolysis and condensation reaction is carried out for at least 4 hours. The functionalized nanoparticles are selected from one of metal nanoparticles such as silver, gold, and copper, or metal oxide nanocrystals such as ferroferric oxide and cobalt trioxide, or sulfide nanoparticles such as copper sulfide. The particle size of the functionalized nanoparticles is 40 to 400 nm, and the specific particle size is selected according to needs.

[0037] S2. Functionalized core-shell particles are used as seeds and dispersed in a mixture of deionized water, ethanol, ammonia water and surfactant. After continued stirring and dispersion, organosilane is added and the reaction is continued with stirring. The reaction liquid obtained after the reaction is subjected to magnetic separation and water washing and alcohol washing to obtain a solid product. After drying, functionalized ordered mesoporous organosilica microspheres with a Yolk-Shell structure are obtained.

[0038] In this step, the surfactant is an alkyl (C n H 2n+1 ) one or more quaternary ammonium salt surfactants, n = 12-18; the organosilane is selected from at least one of 1,2-bis(triethoxysilyl)ethane, 1,2-bis(trimethoxysilyl)ethane, and bis-[γ-(triethoxysilyl)propyl]-tetrasulfide, or a mixture of at least one of 1,2-bis(triethoxysilyl)ethane, 1,2-bis(trimethoxysilyl)ethane, and bis-[γ-(triethoxysilyl)propyl]-tetrasulfide and ethyl orthosilicate.

[0039] The amorphous silica shell layer obtained in step S1 will self-dissolve during the process of forming the ordered mesoporous organosilicon outer shell layer in step S2, that is, microspheres with Yolk-Shell structure can be obtained without "post-etching" treatment.

[0040] The functionalized, ordered mesoporous organosilicon microspheres with a Yolk-Shell structure prepared by the above method include an inner core and a shell coating the outer core, with a gap between the inner core and the shell. The inner core is a functionalized nanoparticle (such as metal nanoparticles such as silver, gold, and copper, metal oxide nanocrystals such as ferroferric oxide and cobalt trioxide, or sulfide nanoparticles such as copper sulfide) that has good dispersibility and stability in alkaline solutions, while the shell is an ordered mesoporous organosilicon shell containing organic functional groups (primarily determined by the type of organosilane). The mesopore diameter is 2 to 4 nm, and the thickness of the ordered mesoporous organosilicon shell is 40 to 200 nm. The desired ordered mesoporous organosilicon shell thickness and mesopore diameter can be achieved by adjusting the ratio of the reactants during the preparation process.

[0041] The specific embodiments are as follows:

[0042] Example 1

[0043] ① Disperse 100.0 mg of Fe3O4 nanocrystals (90 nm in diameter) in a mixture containing 80.0 mL of ethanol, 20.0 mL of deionized water, and 2.0 mL of 5.0 mol / mL ammonia. After uniform dispersion, add 100.0 μL of ethyl orthosilicate and react in a 25°C water bath with continuous stirring for 12 hours. The reaction solution is magnetically separated and washed three times with water and three times with alcohol. Dry in a 60°C oven for 12 hours to obtain Fe3O4@SiO2 core-shell particles.

[0044] ② The Fe3O4@SiO2 core-shell particles obtained in step ① were used as seeds and dispersed in a mixture containing 90.0mL of deionized water, 30.0mL of ethanol, 1.2mL of ammonia (concentration of 5.0mol / mL), and 165mg of hexadecyltrimethylammonium bromide. After stirring and dispersing evenly, 200.0μL of 1,2-bis(triethoxysilyl)ethane was added and the mixture was stirred continuously in a 25°C water bath for 12 hours. The reaction solution was magnetically separated and washed three times with water and three times with alcohol, and then dried in a 60°C oven for 12 hours to obtain Fe3O4@viod@PMO microspheres with a Yolk-Shell structure.

[0045] Comparative Example 1

[0046] ① Disperse 100.0 mg of Fe3O4 nanocrystals (70 nm in diameter) in a mixture containing 80.0 mL of ethanol, 20.0 mL of deionized water, and 2.0 mL of 5.0 mol / mL ammonia. After uniform dispersion, add 100.0 μL of ethyl orthosilicate and incubate in a 25°C water bath with continuous stirring for 12 hours. The reaction mixture is magnetically separated and washed three times with water and three times with alcohol. Dry in a 60°C oven for 12 hours to obtain Fe3O4@SiO2 core-shell particles.

[0047] ② The Fe3O4@SiO2 core-shell particles obtained in step ① were used as seeds and dispersed in a mixture containing 90.0mL of deionized water, 30.0mL of ethanol, 1.2mL of ammonia water (concentration of 5.0mol / mL), and 165mg of hexadecyltrimethylammonium bromide. After stirring and dispersing evenly, 200.0μL of ethyl orthosilicate was added and the mixture was stirred continuously in a 25°C water bath for 12 hours. The reaction solution was magnetically separated and washed three times with water and three times with alcohol, and then dried in a 60°C oven for 12 hours to obtain Fe3O4@SiO2@mSiO2 microspheres with a core-dual shell structure.

[0048] Example 2

[0049] ① Disperse 100.0 mg of Fe3O4 nanocrystals (90 nm in diameter) in a mixture containing 80.0 mL of ethanol, 20.0 mL of deionized water, and 2.0 mL of 5.0 mol / mL ammonia. After uniform dispersion, add 150.0 μL of ethyl orthosilicate and continue stirring in a 25°C water bath for 12 hours. The reaction solution is magnetically separated and washed three times with water and three times with alcohol. Dry in a 60°C oven for 12 hours to obtain Fe3O4@SiO2 core-shell particles.

[0050] ② The Fe3O4@SiO2 core-shell particles obtained in step ① were used as seeds and dispersed in a mixture containing 90.0mL of deionized water, 30.0mL of ethanol, 1.2mL of ammonia (concentration of 5.0mol / mL), and 165mg of hexadecyltrimethylammonium bromide. After stirring and dispersing evenly, 250.0μL of 1,2-bis(triethoxysilyl)ethane was added and the mixture was stirred continuously in a 35°C water bath for 12 hours. The reaction solution was magnetically separated and washed three times with water and three times with alcohol, and then dried in a 60°C oven for 12 hours to obtain Fe3O4@viod@PMO microspheres with a Yolk-Shell structure.

[0051] Example 3

[0052] ① Disperse 100.0 mg of Fe3O4 nanocrystals (125 nm) in a mixture containing 80.0 mL of ethanol, 20.0 mL of deionized water, and 2.0 mL of 5.0 mol / mL ammonia. After uniform dispersion, add 80.0 μL of ethyl orthosilicate and continue stirring in a 25°C water bath for 12 hours. The reaction solution is magnetically separated and washed three times with water and three times with alcohol. Dry in a 60°C oven for 12 hours to obtain Fe3O4@SiO2 core-shell particles.

[0053] ② The Fe3O4@SiO2 core-shell particles obtained in step ① were used as seeds and dispersed in a mixture containing 90.0mL of deionized water, 30.0mL of ethanol, 1.2mL of ammonia (concentration of 5.0mol / mL), and 165mg of hexadecyltrimethylammonium bromide. After stirring and dispersing evenly, 200.0μL of 1,2-bis(trimethoxysilyl)ethane was added and the mixture was stirred continuously in a 25°C water bath for 12 hours. The reaction solution was magnetically separated and washed three times with water and three times with alcohol, and then dried in a 60°C oven for 12 hours to obtain Fe3O4@viod@PMO microspheres with a Yolk-Shell structure.

[0054] Example 4

[0055] ① Disperse 100.0 mg of Fe3O4 nanocrystals (125 nm) in a mixture containing 80.0 mL of ethanol, 20.0 mL of deionized water, and 2.0 mL of 5.0 mol / mL ammonia. After uniform dispersion, add 50.0 μL of ethyl orthosilicate and continue stirring in a 25°C water bath for 12 hours. The reaction solution is magnetically separated and washed three times with water and three times with alcohol. Dry in a 60°C oven for 12 hours to obtain Fe3O4@SiO2 core-shell particles.

[0056] ② The Fe3O4@SiO2 core-shell particles obtained in step ① were used as seeds and dispersed in a mixture containing 90.0mL of deionized water, 30.0mL of ethanol, 1.2mL of ammonia (concentration of 5.0mol / mL), and 165mg of hexadecyltrimethylammonium bromide. After stirring and dispersing evenly, 200.0μL of 1,2-bis(triethoxysilyl)ethane was added and the mixture was stirred continuously in a 25°C water bath for 12 hours. The reaction solution was magnetically separated and washed three times with water and three times with alcohol, and then dried in a 60°C oven for 12 hours to obtain Fe3O4@viod@PMO microspheres with a Yolk-Shell structure.

[0057] Example 5

[0058] ① Disperse 100.0 mg of Fe3O4 nanocrystals (155 nm) in a mixture containing 80.0 mL of ethanol, 20.0 mL of deionized water, and 2.0 mL of 8.0 mol / mL ammonia. After uniform dispersion, add 50.0 μL of ethyl orthosilicate and continue stirring in a 25°C water bath for 12 hours. The reaction solution is magnetically separated and washed three times with water and three times with alcohol. Dry in a 60°C oven for 12 hours to obtain Fe3O4@SiO2 core-shell particles.

[0059] ② The Fe3O4@SiO2 core-shell particles obtained in step ① were used as seeds and dispersed in a mixture containing 90.0mL of deionized water, 30.0mL of ethanol, 1.2mL of ammonia (concentration of 8.0mol / mL), and 165mg of hexadecyltrimethylammonium bromide. After stirring and dispersing evenly, 200.0μL of 1,2-bis(trimethoxysilyl)ethane was added and the mixture was stirred continuously in a 25°C water bath for 12 hours. The reaction solution was magnetically separated and washed three times with water and three times with alcohol, and then dried in a 60°C oven for 12 hours to obtain Fe3O4@viod@PMO microspheres with a Yolk-Shell structure.

[0060] Example 6

[0061] ① Disperse 100.0 mg of Co3O4 nanoparticles (80 nm in diameter) in a mixture containing 80.0 mL of ethanol, 20.0 mL of deionized water, and 2.0 mL of 5.0 mol / mL ammonia. After uniform dispersion, add 150.0 μL of ethyl orthosilicate and react in a 25°C water bath with continuous stirring for 12 hours. The reaction solution is magnetically separated and washed three times with water and three times with alcohol. Dry in a 60°C oven for 12 hours to obtain Co3O4@SiO2 core-shell particles.

[0062] ② The Co3O4@SiO2 core-shell particles obtained in step ① were used as seeds and dispersed in a mixture containing 90.0mL of deionized water, 30.0mL of ethanol, 1.2mL of ammonia (concentration of 5.0mol / mL) and 165mg of hexadecyltrimethylammonium bromide. After stirring and dispersing evenly, 250.0μL of 1,2-bis(triethoxysilyl)ethane was added and the mixture was stirred continuously in a 25°C water bath for 12h. The reaction solution was magnetically separated and washed with water three times and with alcohol three times, and then dried in a 60°C oven for 12h to obtain Co3O4@viod@PMO microspheres with a Yolk-Shell structure.

[0063] Example 7

[0064] ① Disperse 50.0 mg of Ag nanoparticles (approximately 30 nm in diameter) in a mixture containing 80.0 mL of ethanol, 20.0 mL of deionized water, and 2.0 mL of 5.0 mol / mL ammonia. After uniform dispersion, add 50.0 μL of ethyl orthosilicate and continue stirring in a 25°C water bath for 12 hours. The reaction solution is magnetically separated and washed three times with water and three times with alcohol. Dry in a 60°C oven for 12 hours to obtain Ag@SiO2 core-shell particles.

[0065] ② The Ag@SiO2 core-shell particles obtained in step ① were used as seeds and dispersed in a mixture containing 90.0mL of deionized water, 30.0mL of ethanol, 1.2mL of ammonia water (concentration of 5.0mol / mL) and 165mg of hexadecyltrimethylammonium bromide. After stirring and dispersing evenly, 100.0μL of 1,2-bis(triethoxysilyl)ethane was added and stirred in a 25°C water bath for 12h. The reaction solution was magnetically separated and washed with water three times and with alcohol three times, and then dried in a 60°C oven for 12h to obtain Ag@viod@PMO microspheres with Yolk-Shell structure.

[0066] The thickness of the amorphous silica shell in the functionalized core-shell particles prepared in step ① during the preparation of the above examples and comparative examples, as well as the particle size, core diameter, shell thickness, mesopore diameter, and specific surface area of ​​the microspheres finally obtained are shown in Table 1.

[0067] Table 1

[0068]

[0069] TEM images of microspheres prepared in Examples 1-7 ( Figure 1 、 3 -8) It can be seen that the microspheres prepared by the method of the present invention have a typical Yolk-Shell structure, the ordered mesoporous organosilicon shell layer is not dissolved, and the cavity structure is obvious.

[0070] Comparative Example 1 and Comparative Example 1 prepared microspheres TEM images ( Figure 1 、 Figure 2 ) It can be seen that when 1,2-bis(triethoxysilyl)ethane is replaced with ethyl orthosilicate, the resulting microspheres have a solid core-shell structure with no gaps between the core and shell, and their specific surface area decreases (see Table 1). Substituting ethyl orthosilicate for silicone, microspheres were prepared according to the methods of Examples 1-7, and similarly, core-dual shell microspheres were obtained with no gaps between the core and shell.

[0071] Infrared contrast spectra of microspheres prepared by Example 1 and Comparative Example 1 ( Figure 9 ) It can be seen that the ordered mesoporous organosilicon shell prepared in Example 1 contains organic functional groups.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing functionalized ordered mesoporous organosilicon microspheres with Yolk-Shell structure, characterized in that: The microspheres are prepared by the following steps: S1. Using functionalized nanoparticles as cores, a layer of amorphous silica is coated on the surface of the functionalized nanoparticles through the hydrolysis and polycondensation of silicon source precursors at room temperature to obtain functionalized core-shell particles. S2. Functionalized core-shell particles are used as seeds and dispersed in a mixture of deionized water, ethanol, ammonia water and a surfactant. After being uniformly dispersed by stirring, organic silane is added and the reaction is continued by stirring to obtain functionalized ordered mesoporous organic silicon microspheres with a Yolk-Shell structure; the organic silane is selected from at least one of 1,2-bis(triethoxysilyl)ethane, 1,2-bis(trimethoxysilyl)ethane, and bis-[γ-(triethoxysilyl)propyl]-tetrasulfide, or a mixture of at least one of 1,2-bis(triethoxysilyl)ethane, 1,2-bis(trimethoxysilyl)ethane, and bis-[γ-(triethoxysilyl)propyl]-tetrasulfide and ethyl orthosilicate.

2. The method for preparing functionalized ordered mesoporous organosilicon microspheres having a Yolk-Shell structure according to claim 1, characterized in that: The microspheres include an inner core and a shell covering the outer core, with a gap between the inner core and the shell. The inner core is a functionalized nanoparticle with good dispersibility and stability in an alkaline solution, and the shell is an ordered mesoporous organosilicon shell.

3. The method for preparing functionalized ordered mesoporous organosilicon microspheres having a Yolk-Shell structure according to claim 2, characterized in that: The functionalized nanoparticles are selected from metal nanoparticles and metal oxide nanocrystals; the particle size of the functionalized nanoparticles is 40-400 nm.

4. The method for preparing functionalized ordered mesoporous organosilicon microspheres having a Yolk-Shell structure according to claim 3, characterized in that: The metal nanoparticles are silver nanoparticles; the metal oxide nanocrystals are selected from one of ferroferric oxide nanocrystals and cobalt oxide nanocrystals; and the particle size of the functionalized nanoparticles is 30 to 155 nm.

5. The method for preparing functionalized ordered mesoporous organosilicon microspheres having a Yolk-Shell structure according to claim 2, characterized in that: The mesopore diameter of the ordered mesoporous organosilicon shell layer is 2 to 4 nm, and the thickness of the ordered mesoporous organosilicon shell layer is 40 to 200 nm.

6. The method for preparing functionalized ordered mesoporous organosilicon microspheres having a Yolk-Shell structure according to claim 5, characterized in that: The mesopore diameter of the ordered mesoporous organosilicon shell is 2.43~2.52nm, and the thickness of the ordered mesoporous organosilicon shell is 18~50nm.

7. The method for preparing functionalized ordered mesoporous organosilicon microspheres having a Yolk-Shell structure according to claim 1, characterized in that: The specific preparation steps of the functionalized core-shell particles in step S1 are as follows: the functionalized nanoparticles are uniformly dispersed in an alkaline mixture containing ethanol, deionized water, and an alkaline substance, a silicon source precursor is added, and the mixture is continuously stirred in a water bath at room temperature for 12 hours to obtain functionalized core-shell particles; the silicon source precursor is selected from one or more of ethyl orthosilicate, methyl orthosilicate, sodium silicate, or silicon tetrachloride.

8. The method for preparing functionalized ordered mesoporous organosilicon microspheres having a Yolk-Shell structure according to claim 7, characterized in that: In step S1, the ratio of the functionalized nanoparticles to ethanol, deionized water, alkaline substance, and silicon source precursor is (50-100) mg:80 ml:20 ml:2 ml:(50-150) μL, the alkaline substance is ammonia water with a concentration of 5.0-8.0 mol / mL; the silicon source precursor is ethyl orthosilicate; and the thickness of the amorphous silica shell layer in the functionalized core-shell particles is 5-100 nm.

9. The method for preparing functionalized ordered mesoporous organosilicon microspheres having a Yolk-Shell structure according to claim 1, characterized in that: In step S2, the reaction solution obtained after the reaction is subjected to magnetic separation and washed with water and alcohol to obtain a solid product, which is then dried to obtain functionalized ordered mesoporous organosilicon microspheres with a Yolk-Shell structure; In step S2, the surfactant is one or more alkyl quaternary ammonium salt surfactants.

10. The method for preparing functionalized ordered mesoporous organosilicon microspheres having a Yolk-Shell structure according to claim 9, characterized in that: The ratio of deionized water, ethanol, ammonia, surfactant, and organosilane used in step S2 to the functionalized nanoparticles described in step S1 is 90.0 mL: 30.0 mL: 1.2 mL: 165 mg: (100-250) μL: (50-100) mg. The concentration of ammonia is 5.0-8.0 mol / mL. The surfactant is hexadecyltrimethylammonium bromide. The organosilane is 1,2-bis(triethoxysilyl)ethane or 1,2-bis(trimethoxysilyl)ethane. The reaction temperature in step S2 is 25-35°C.

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