Mesoporous silica microsphere, preparation method and application thereof

Abstract

The invention belongs to the technical field of chromatographic filling, and particularly relates to mesoporous silica microspheres, a preparation method and application. According to the preparation method, tetraethylenepentamine functional modified template microspheres and oligomeric silica anions generated by hydrolysis of a silicon source are subjected to an electrostatic anchoring effect, so that self-nucleation of the silicon source is inhibited; the surface of the template microsphere is covered by a lying configuration, so that the steric hindrance is reduced, the diffusion of a silicon precursor in a silicon source solution is promoted, and the yield of the mesoporous silica microsphere is improved; the surface of mesoporous silica is grafted and modified by octadecyl trichlorosilane silicon hydroxyl to form a highly crosslinked Si-O-Si skeleton, so that the mechanical strength of the microspheres is improved, the column efficiency loss is reduced, and the comprehensive yield and performance of high performance liquid chromatography are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of chromatographic packing, and particularly relates to a mesoporous silica microsphere, a preparation method thereof and an application thereof. Background Art

[0002] High performance liquid chromatography (HPLC) is widely used in the fields of biology, chemical engineering, pharmacy, food analysis, environmental protection, etc., and is an important tool for the separation and analysis of complex samples. As the core of HPLC, chromatographic packing is the most crucial part in chromatographic research. At present, mesoporous silica microspheres are the most widely used chromatographic packing, having advantages such as large specific surface area, low dielectric constant, low expansion coefficient, strong adsorption, chemical stability, excellent thermal and shock resistance, and easy dispersion.

[0003] Currently, the main preparation methods of mesoporous silica microspheres include sol-gel method, microemulsion method, spray drying method and polymerization-induced colloidal aggregation method. The sol-gel method is to add a surfactant to a solution, and then remove the template agent by calcination or solution extraction to obtain porous silica microspheres; the silica microspheres obtained by the microemulsion method have a wide particle size distribution and must undergo strict particle size screening; the polymerization-induced colloidal aggregation method cannot be maturely applied on a large scale due to limitations such as silica sol; the silica particles prepared by the spray drying method have poor sphericity, wide particle size distribution and poor mechanical strength, and basically cannot meet the requirements of high performance liquid chromatography packing. It is very difficult to prepare mesoporous silica spheres with uniform particle size and good dispersion by the existing technology, and usually has high cost and low column efficiency. Summary of the Invention

[0004] The purpose of the present invention is to provide a mesoporous silica microsphere, a preparation method thereof and an application thereof to solve the above technical problems.

[0005] To achieve the above technical purpose, the technical solution of the present invention is as follows: A preparation method of a mesoporous silica microsphere, comprising the following steps: S1. Mix the silica sol aqueous phase W1 and the oil phase O at a mass ratio of 1:1, and form a W1 / O primary emulsion by high-speed homogenization; then inject the W1 / O primary emulsion into the outer aqueous phase W2 at a mass ratio of (W1 / O):W2 = 1:5, and homogenize at 200 rpm and 20 °C for 3 h to form a W1 / O / W2 double emulsion; S2. Pulse-add a 0.05-0.1 wt% tetraethoxysilane solution and a 0.02-0.08 wt% cetyltrimethylammonium bromide solution to the W1 / O / W2 double emulsion at a mass ratio of 1:1-2, disperse by ultrasonic wave at 300 W for 20 min, and react at 40 °C for 6 h to obtain a silicon source solution; S3. Under a nitrogen atmosphere, at a dropping rate of 0.2 mL / min, the silicon source solution was dropped into the modified glycidyl methacrylate co-ethylene glycol dimethacrylate microsphere solution, the pH was adjusted to 5.5 - 6.5, and the mixture was stirred and reacted at 30 °C for 2 - 4 h, followed by vacuum infiltration for 30 - 60 min. After the obtained microspheres were calcined in stages and dried, the initial mesoporous silica microspheres were obtained. Among them, the mass ratio of the modified glycidyl methacrylate co-ethylene glycol dimethacrylate microsphere solution to the silicon source solution was 2:1 - 3; S4. At a mass ratio of 1:25 and at 120 °C, the initial mesoporous silica microspheres were immersed in a 30 wt% hydrochloric acid solution for 6 h. After washing and drying, they were dispersed in toluene, octadecyltrichlorosilane was added, and the mixture was refluxed at 125 °C for 24 h. Finally, the obtained product was washed successively with toluene and ethanol and dried to obtain mesoporous silica microspheres. Among them, the mass ratio of octadecyltrichlorosilane to the initial mesoporous silica microspheres was 1:1.

[0006] As a further improvement, in step S1, the preparation method of the silicon sol aqueous phase W1 is as follows: The silane coupling agent and sodium carboxymethylcellulose were dissolved in deionized water and ultrasonically dispersed at 600 W for 30 min. Among them, the mass fractions of the silane coupling agent and sodium carboxymethylcellulose dissolved in deionized water were 1.5 - 2.0 wt% and 0.1 - 0.5 wt% respectively, and the viscosity of the silicon sol aqueous phase was 500 - 800 mPa·s at room temperature.

[0007] As a further improvement, in step S1, the preparation method of the oil phase O is as follows: According to a solid-liquid ratio of 1:30, polyglycerol ricinoleate was dissolved in cyclohexane / liquid paraffin, and the volume ratio of cyclohexane to liquid paraffin was 3:1. The preparation method of the outer aqueous phase W2 is as follows: According to a volume ratio of 1:1, a 2 wt% polyvinyl alcohol solution and a 0.4 wt% sodium dodecyl sulfate solution were mixed and stirred at 300 rpm for 12 min.

[0008] As a further improvement, in step S2, the dropping method of the tetraethoxysilane solution and the cetyltrimethylammonium bromide solution is pulsed dropping: The tetraethoxysilane solution and the cetyltrimethylammonium bromide solution were alternately added every 10 min, and the total number of feeding times was 6 - 10 times.

[0009] As a further improvement, in step S3, the preparation method of the modified poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) microsphere solution is as follows: Disperse poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) microspheres in deionized water, add tetraethylenepentamine after ultrasonic treatment, react at 80 °C for 12 h, wash and dry after the reaction; Mix the dried microspheres with isopropanol and deionized water, and perform ultrasonic treatment at 600 W for 15 min to obtain the modified poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) microsphere solution; Among them, the mass ratio of poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) microspheres to tetraethylenepentamine is 1:2 - 4; The mass ratio of the dried microspheres to isopropanol and deionized water is 1:20:4.

[0010] As a further improvement, the preparation method of the poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) microspheres is as follows: Dissolve glycidyl methacrylate, ethylene dimethacrylate, and cyclohexanol in deionized water, mix evenly and emulsify for 30 min to obtain an emulsified mixture; Add the emulsified mixture to a styrene seed suspension, react in a water bath at 70 °C for 24 h, wash the obtained microspheres with water, remove cyclohexanol by toluene extraction, and dry at 50 °C for 6 h to obtain poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) microspheres; Among them, the mass ratio of glycidyl methacrylate, ethylene dimethacrylate, and cyclohexanol is 1:1 - 3:2.

[0011] As a further improvement, the preparation method of the styrene seed suspension is as follows: Under a nitrogen atmosphere, disperse and polymerize styrene in an anhydrous ethanol medium, add dicyclohexylcarbodiimide and polyvinylpyrrolidone, mix evenly and then perform ultrasonic treatment, and then stir and react at 70 °C and 120 r / min for 24 h, centrifuge and separate, wash, and dry to obtain styrene seeds; Disperse the styrene seeds in deionized water, add benzoyl peroxide and polyvinyl alcohol, perform ultrasonic dispersion, and then stir in a water bath at 30 °C for 30 min to obtain a styrene seed suspension; Among them, the addition amounts of dicyclohexylcarbodiimide and polyvinylpyrrolidone are 5 wt% and 1 wt% of the polymerized styrene respectively; The mass ratio of styrene seeds, benzoyl peroxide to polyvinyl alcohol is 1:0.2 - 0.5:3.

[0012] The present invention also provides a mesoporous silica microsphere.

[0013] The present invention also provides an application of the mesoporous silica microsphere in high performance liquid chromatography. According to a solid-liquid ratio of 1:20, disperse the mesoporous silica microsphere in a toluene solution, and load it into a stainless steel column in a suspension manner at 40 MPa for high performance liquid chromatography.

[0014] Due to the adoption of the above technical solutions, the beneficial effects of the present invention are: 1. Functionalized and modified with tetraethylenepentamine, protonated amino groups are formed on the surface of glycidyl methacrylate co-ethylene glycol dimethacrylate microspheres, which combine with the oligomeric siloxyanions ([Si(OH)3 - ) produced by the hydrolysis of the silicon source solution through strong electrostatic interaction, inhibiting the self-nucleation of the silicon source, achieving the directional enrichment of the silicon source on the surface of the template microspheres, increasing the density of nucleation sites, decreasing the self-nucleation rate, and improving the yield and dispersibility of mesoporous silica microspheres.

[0015] 2. Tetraethylenepentamine molecules are anchored at multiple points, binding to the epoxy groups on the surface of glycidyl methacrylate co-ethylene glycol dimethacrylate microspheres to form a lying graft configuration, enabling the silicon precursor to be evenly embedded in the pores of the polymer template, forming a three-dimensional interpenetrating network structure; reducing steric hindrance, promoting the diffusion of the silicon precursor in the silicon source solution, increasing the diffusion flux of the silicon precursor, and improving the formation rate of mesoporous silica.

[0016] 3. Octadecyltrichlorosilane modifies the Si-OH groups on the surface of mesoporous silica microspheres through silicon hydroxyl grafting, forming a highly cross-linked Si-O-Si skeleton, improving the mechanical strength of mesoporous silica microspheres, reducing column efficiency loss; effectively reducing the exposure of silicon hydroxyl groups, decreasing non-specific adsorption with the sample for separation and purification, reducing hydrogen bond and ion exchange interactions between the sample and silicon hydroxyl groups, reducing the tailing factor, and improving the separation efficiency of HPCL. Description of the Drawings

[0017] Figure 1 is the particle size distribution diagram of mesoporous silica microspheres obtained in different examples; among them, curves a, b, c, d, and e are the particle size distribution curves of mesoporous silica microspheres obtained in Comparative Example 1, Comparative Example 2, Example 1, Example 2, and Example 3, respectively; Figure 2 is the scanning electron microscope image of mesoporous silica microspheres; among them, Figure a is the scanning electron microscope image of mesoporous silica microspheres obtained in Comparative Example 1; Figure b is the scanning electron microscope image of mesoporous silica microspheres obtained in Comparative Example 2; Figure c is the scanning electron microscope image of mesoporous silica microspheres obtained in Example 1. Detailed Embodiments

[0018] The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. However, those skilled in the art will understand that the following described embodiments are some embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention. For those conditions not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0019] Example 1: Preparation and application of mesoporous silica microspheres, comprising the following steps: 1. Dissolve the silane coupling agent and sodium carboxymethyl cellulose in deionized water, and disperse them by ultrasonic wave at 600W for 30min to obtain the aqueous phase W1 of the silica solution; wherein, the mass fractions of the silane coupling agent and sodium carboxymethyl cellulose dissolved in deionized water are 1.5wt% and 0.1wt% respectively; the viscosity of the aqueous phase of the silica solution at room temperature is 500mPa·s.

[0020] 2. According to the solid-liquid ratio of 1:30, dissolve polyglycerol ricinoleate in cyclohexane / liquid paraffin, and the volume ratio of cyclohexane to liquid paraffin is 3:1 to obtain the oil phase O; according to the mass ratio of 1:1, mix the aqueous phase W1 of the silica solution with the oil phase O, and homogenize at 12000rpm for 20min to form the W1 / O primary emulsion.

[0021] 3. Mix the 2wt% polyvinyl alcohol solution and the 0.4wt% sodium dodecyl sulfate solution according to the volume ratio of 1:1, and stir at 300rpm for 12min to obtain the outer aqueous phase W2; according to the mass ratio (W1 / O):W2 = 1:5, inject the W1 / O primary emulsion into the outer aqueous phase W2, and react at 200rpm and 20°C for 3h to form the W1 / O / W2 double emulsion.

[0022] 4. According to the mass ratio of 1:1, pulse-add the 0.05wt% tetraethoxysilane solution and the 0.02wt% cetyltrimethylammonium bromide solution to the W1 / O / W2 double emulsion every 10min, and the total number of feeding times is 6 times. Disperse by ultrasonic wave at 300W for 20min and react at 40°C for 6h to obtain the silicon source solution; 5. Under a nitrogen atmosphere, styrene was dispersed and polymerized in an absolute ethanol medium. Dicyclohexylcarbodiimide and polyvinylpyrrolidone were added. After stirring and mixing at 600 r / min for 20 min, ultrasonic dispersion was carried out at 300 W for 5 min, and then the reaction was carried out with stirring at 70 °C and 120 r / min for 24 h. After centrifugal separation, it was washed with absolute ethanol and distilled water and dried at 60 °C for 2 h to obtain styrene seeds. Among them, the mass ratio of polymerized styrene to absolute ethanol was 1:60; the addition amounts of dicyclohexylcarbodiimide and polyvinylpyrrolidone were 5 wt% and 1 wt% of polymerized styrene, respectively.

[0023] 6. According to the solid-liquid ratio of 1:60, the styrene seeds were dispersed in deionized water. Benzoyl peroxide and polyvinyl alcohol were added. After ultrasonic dispersion at 300 W for 5 min, water bath stirring was carried out at 30 °C for 30 min to obtain a styrene seed suspension. Among them, the mass ratio of styrene seeds, benzoyl peroxide and polyvinyl alcohol was 1:0.2:3.

[0024] 7. Glycidyl methacrylate, ethylene dimethacrylate and cyclohexanol were dissolved in deionized water, mixed evenly and emulsified for 30 min to obtain an emulsified mixture. According to the volume ratio of 1:2, the emulsified mixture was added to the styrene seed suspension, and the reaction was carried out in a water bath at 70 °C for 24 h. The obtained microspheres were washed with water, and cyclohexanol was removed by extraction with toluene, and then dried at 50 °C for 6 h to obtain glycidyl methacrylate copolymerized ethylene dimethacrylate microspheres. Among them, the mass ratio of glycidyl methacrylate, ethylene dimethacrylate and cyclohexanol was 1:1:2.

[0025] 8. According to the mass ratio of 1:40, the glycidyl methacrylate copolymerized ethylene dimethacrylate microspheres were dispersed in deionized water, ultrasonic treatment was carried out at 600 W for 5 min, tetraethylenepentamine was added, and the reaction was carried out at 80 °C for 12 h. After the reaction, it was washed, dried at 60 °C for 3 h, and the dried microspheres were mixed with isopropanol and deionized water, and ultrasonic treatment was carried out at 600 W for 15 min to obtain a modified glycidyl methacrylate copolymerized ethylene dimethacrylate microsphere solution. Among them, the mass ratio of glycidyl methacrylate copolymerized ethylene dimethacrylate microspheres to tetraethylenepentamine was 1:2; the mass ratio of the dried microspheres to isopropanol and deionized water was 1:20:4.

[0026] 9. Under a nitrogen atmosphere, at a dropping rate of 0.2 mL / min, a silicon source solution was dropped into the solution of modified glycidyl methacrylate copolymerized ethylene glycol dimethacrylate microspheres. 0.1 M ammonia water was added dropwise to adjust the pH to 5.5, and the mixture was stirred at 30 °C for 2 h and then vacuum infiltrated for 30 min. The obtained microspheres were washed with deionized water and then subjected to staged calcination: first, it was heated to 280 °C at a rate of 2 °C / min and held for 1 h, then heated to 500 °C at a rate of 5 °C / min and cured for 2 h. After calcination, the obtained microspheres were subjected to CO2 supercritical drying at 10 MPa and 45 °C for 3 h to obtain the initial mesoporous silica microspheres; among them, the mass ratio of the solution of modified glycidyl methacrylate copolymerized ethylene glycol dimethacrylate microspheres to the silicon source solution was 2:1.

[0027] 10. At a mass ratio of 1:25 and at 120 °C, the initial mesoporous silica microspheres were immersed in a 30 wt% hydrochloric acid solution for 6 h, then washed with deionized water until neutral, and then dried at 120 °C for 8 h. The obtained product was dispersed in toluene, octadecyltrichlorosilane was added, and the mixture was refluxed at 125 °C for 24 h. Finally, the obtained product was washed successively with toluene and ethanol and dried at 60 °C for 12 h to obtain mesoporous silica microspheres; at a solid-liquid ratio of 1:20, the mesoporous silica microspheres were dispersed in a toluene solution and loaded into a stainless steel column in a suspension manner at 40 MPa for high-performance liquid chromatography; among them, the mass ratio of octadecyltrichlorosilane to the initial mesoporous silica microspheres was 1:1.

[0028] Example 2: The preparation and application of mesoporous silica microspheres, including the following steps: 1. The silane coupling agent and sodium carboxymethylcellulose were dissolved in deionized water and ultrasonically dispersed at 600 W for 30 min to obtain the aqueous phase W1 of the silicon solution; among them, the mass fractions of the silane coupling agent and sodium carboxymethylcellulose dissolved in deionized water were 1.8 wt% and 0.3 wt% respectively; the viscosity of the aqueous phase W1 of the silicon solution at room temperature was 700 mPa·s.

[0029] 2. At a solid-liquid ratio of 1:30, polyglycerol ricinoleate was dissolved in cyclohexane / liquid paraffin, and the volume ratio of cyclohexane to liquid paraffin was 3:1 to obtain the oil phase O; at a mass ratio of 1:1, the aqueous phase W1 of the silicon solution and the oil phase O were mixed and homogenized at 12000 rpm for 20 min to form the W1 / O primary emulsion.

[0030] 3. A 2 wt% polyvinyl alcohol solution and a 0.4 wt% sodium dodecyl sulfate solution were mixed at a volume ratio of 1:1 and stirred at 300 rpm for 12 min to obtain the outer aqueous phase W2; at a mass ratio of (W1 / O):W2 = 1:5, the W1 / O primary emulsion was injected into the outer aqueous phase W2, and the reaction was carried out at 200 rpm and 20 °C for 3 h to form the W1 / O / W2 double emulsion.

[0031] 4. Add a 0.08 wt% tetraethoxysilane solution and a 0.05 wt% cetyltrimethylammonium bromide solution to the W1 / O / W2 double emulsion in a mass ratio of 1:1.5 in a pulsed manner every 10 min. The total number of feeding times is 8 times. Then, disperse it with ultrasonic waves at 300 W for 20 min and react at 40 °C for 6 h to obtain a silicon source solution. 5. Under a nitrogen atmosphere, disperse and polymerize styrene in an absolute ethanol medium. Add dicyclohexylcarbodiimide and polyvinylpyrrolidone, stir and mix at 600 r / min for 20 min, then disperse with ultrasonic waves at 300 W for 5 min. Then, stir and react at 70 °C and 120 r / min for 24 h. After centrifugal separation, wash with absolute ethanol and distilled water, and dry at 60 °C for 2 h to obtain styrene seeds. Among them, the mass ratio of polymerized styrene to absolute ethanol is 1:60; the addition amounts of dicyclohexylcarbodiimide and polyvinylpyrrolidone are 5 wt% and 1 wt% of polymerized styrene, respectively.

[0032] 6. Disperse the styrene seeds in deionized water according to a solid-liquid ratio of 1:60, add benzoyl peroxide and polyvinyl alcohol, disperse with ultrasonic waves at 300 W for 5 min, and then stir in a water bath at 30 °C for 30 min to obtain a styrene seed suspension. Among them, the mass ratio of styrene seeds, benzoyl peroxide and polyvinyl alcohol is 1:0.2:3.

[0033] 7. Dissolve glycidyl methacrylate, ethylene dimethacrylate and cyclohexanol in deionized water, mix evenly and emulsify for 30 min to obtain an emulsified mixture. Add the emulsified mixture to the styrene seed suspension according to a volume ratio of 1:2, and react in a water bath at 70 °C for 24 h. Wash the obtained microspheres with water, remove cyclohexanol by toluene extraction, and dry at 50 °C for 6 h to obtain glycidyl methacrylate co-ethylene dimethacrylate microspheres. Among them, the mass ratio of glycidyl methacrylate, ethylene dimethacrylate and cyclohexanol is 1:2:2.

[0034] 8. Disperse the glycidyl methacrylate co-ethylene dimethacrylate microspheres in deionized water according to a mass ratio of 1:40, treat with ultrasonic waves at 600 W for 5 min, add tetraethylenepentamine, and react at 80 °C for 12 h. After the reaction, wash and dry at 60 °C for 3 h. Mix the dried microspheres with isopropanol and deionized water, and treat with ultrasonic waves at 600 W for 15 min to obtain a modified glycidyl methacrylate co-ethylene dimethacrylate microsphere solution. Among them, the mass ratio of glycidyl methacrylate co-ethylene dimethacrylate microspheres to tetraethylenepentamine is 1:3; the mass ratio of the dried microspheres to isopropanol and deionized water is 1:20:4.

[0035] 9. Under a nitrogen atmosphere, the silicon source solution was dropped into the modified glycidyl methacrylate co-ethylene glycol dimethacrylate microsphere solution at a dropping rate of 0.2 mL / min. 0.1 M ammonia water was added dropwise to adjust the pH to 6.0, and the mixture was stirred and reacted at 30 °C for 3 h, followed by vacuum infiltration for 50 min. The obtained microspheres were washed with deionized water and then subjected to segmented calcination: first, it was heated to 280 °C at a rate of 2 °C / min and held for 1 h, then heated to 500 °C at a rate of 5 °C / min and cured for 2 h. After calcination, the obtained microspheres were subjected to CO2 supercritical drying at 10 MPa and 45 °C for 4 h to obtain the initial mesoporous silica microspheres; among them, the mass ratio of the modified glycidyl methacrylate co-ethylene glycol dimethacrylate microsphere solution to the silicon source solution was 2:2.

[0036] 10. At a mass ratio of 1:25 and 120 °C, the initial mesoporous silica microspheres were immersed in a 30 wt% hydrochloric acid solution for 6 h, then washed with deionized water until neutral, and then dried at 120 °C for 8 h. The obtained product was dispersed in toluene, octadecyltrichlorosilane was added, and the mixture was refluxed at 125 °C for 24 h. Finally, the obtained product was washed successively with toluene and ethanol and dried at 60 °C for 12 h to obtain mesoporous silica microspheres; at a solid-liquid ratio of 1:20, the mesoporous silica microspheres were dispersed in a toluene solution and loaded into a stainless steel column in a suspension manner at 40 MPa for high-performance liquid chromatography; among them, the mass ratio of octadecyltrichlorosilane to the initial mesoporous silica microspheres was 2:1.

[0037] Example 3: The preparation and application of a mesoporous silica microsphere, including the following steps: 1. The silane coupling agent and sodium carboxymethylcellulose were dissolved in deionized water and ultrasonicated for 30 min at 600 W to obtain the aqueous phase W1 of the silicon solution; among them, the mass fractions of the silane coupling agent and sodium carboxymethylcellulose dissolved in deionized water were 2.0 wt% and 0.5 wt% respectively; the viscosity of the aqueous phase W1 of the silicon solution at room temperature was 800 mPa·s.

[0038] 2. At a solid-liquid ratio of 1:30, polyglycerol ricinoleate was dissolved in cyclohexane / liquid paraffin, and the volume ratio of cyclohexane to liquid paraffin was 3:1 to obtain the oil phase O; at a mass ratio of 1:1, the aqueous phase W1 of the silicon solution was mixed with the oil phase O and homogenized at 12000 rpm for 20 min to form the W1 / O primary emulsion.

[0039] 3. A 2 wt% polyvinyl alcohol solution and a 0.4 wt% sodium dodecyl sulfate solution were mixed at a volume ratio of 1:1 and stirred at 300 rpm for 12 min to obtain the outer aqueous phase W2; at a mass ratio of (W1 / O):W2 = 1:5, the W1 / O primary emulsion was injected into the outer aqueous phase W2, and the reaction was carried out at 200 rpm and 20 °C for 3 h to form the W1 / O / W2 double emulsion.

[0040] 4. Add a 0.05 wt% tetraethoxysilane solution and a 0.02 wt% cetyltrimethylammonium bromide solution to the W1 / O / W2 double emulsion in a mass ratio of 1:2 in a pulsed manner every 10 min. The total number of feeding times is 10 times. Then, disperse it with ultrasound at 300 W for 20 min and react at 40 °C for 6 h to obtain a silicon source solution. 5. Disperse and polymerize styrene in an anhydrous ethanol medium under a nitrogen atmosphere. Add dicyclohexylcarbodiimide and polyvinylpyrrolidone, stir and mix at 600 r / min for 20 min, then disperse with ultrasound at 300 W for 5 min. Then, stir and react at 70 °C and 120 r / min for 24 h. After centrifugal separation, wash with anhydrous ethanol and distilled water, and dry at 60 °C for 2 h to obtain styrene seeds. Among them, the mass ratio of polymerized styrene to anhydrous ethanol is 1:60; the addition amounts of dicyclohexylcarbodiimide and polyvinylpyrrolidone are 5 wt% and 1 wt% of polymerized styrene, respectively.

[0041] 6. Disperse the styrene seeds in deionized water at a solid-liquid ratio of 1:60, add benzoyl peroxide and polyvinyl alcohol, disperse with ultrasound at 300 W for 5 min, and then stir in a water bath at 30 °C for 30 min to obtain a styrene seed suspension. Among them, the mass ratio of styrene seeds, benzoyl peroxide and polyvinyl alcohol is 1:0.5:3.

[0042] 7. Dissolve glycidyl methacrylate, ethylene dimethacrylate and cyclohexanol in deionized water, mix evenly and emulsify for 30 min to obtain an emulsified mixture. Add the emulsified mixture to the styrene seed suspension in a volume ratio of 1:2, and react in a water bath at 70 °C for 24 h. Wash the obtained microspheres with water, remove cyclohexanol by toluene extraction, and dry at 50 °C for 6 h to obtain glycidyl methacrylate co-ethylene dimethacrylate microspheres. Among them, the mass ratio of glycidyl methacrylate, ethylene dimethacrylate and cyclohexanol is 1:3:2.

[0043] 8. Disperse the glycidyl methacrylate co-ethylene dimethacrylate microspheres in deionized water at a mass ratio of 1:40, ultrasonically treat at 600 W for 5 min, add tetraethylenepentamine, and react at 80 °C for 12 h. After the reaction, wash and dry at 60 °C for 3 h. Mix the dried microspheres with isopropanol and deionized water, and ultrasonically treat at 600 W for 15 min to obtain a modified glycidyl methacrylate co-ethylene dimethacrylate microsphere solution. Among them, the mass ratio of glycidyl methacrylate co-ethylene dimethacrylate microspheres to tetraethylenepentamine is 1:4; the mass ratio of the dried microspheres to isopropanol and deionized water is 1:20:4.

[0044] 9. Under a nitrogen atmosphere, at a dropping rate of 0.2 mL / min, the silicon source solution was dropped into the modified glycidyl methacrylate copolymerized ethylene glycol dimethacrylate microsphere solution. 0.1 M ammonia water was added dropwise to adjust the pH to 6.5, and the mixture was stirred and reacted at 30 °C for 4 h, followed by vacuum infiltration for 60 min. The obtained microspheres were washed with deionized water and then subjected to staged calcination: first heated to 280 °C at a rate of 2 °C / min and held for 1 h, then heated to 500 °C at a rate of 5 °C / min and cured for 2 h. After calcination, the obtained microspheres were subjected to CO2 supercritical drying at 10 MPa and 45 °C for 3 h to obtain the initial mesoporous silica microspheres. Among them, the mass ratio of the modified glycidyl methacrylate copolymerized ethylene glycol dimethacrylate microsphere solution to the silicon source solution was 2:3.

[0045] 10. At a mass ratio of 1:25 and 120 °C, the initial mesoporous silica microspheres were immersed in a 30 wt% hydrochloric acid solution for 6 h, then washed with deionized water until neutral, and then dried at 120 °C for 8 h. The obtained product was dispersed in toluene, octadecyltrichlorosilane was added, and the mixture was refluxed at 125 °C for 24 h. Finally, the obtained product was washed successively with toluene and ethanol and dried at 60 °C for 12 h to obtain mesoporous silica microspheres. At a solid-liquid ratio of 1:20, the mesoporous silica microspheres were dispersed in a toluene solution and loaded into a stainless steel column in a suspension manner at 40 MPa for high performance liquid chromatography. Among them, the mass ratio of octadecyltrichlorosilane to the initial mesoporous silica microspheres was 3:1.

[0046] The difference between Comparative Example 1 and Example 1 is that the glycidyl methacrylate copolymerized ethylene glycol dimethacrylate microspheres were not modified, and the specific steps are as follows: 1. The silane coupling agent and sodium carboxymethylcellulose were dissolved in deionized water and ultrasonically dispersed at 600 W for 30 min to obtain the aqueous phase W1 of the silica sol. Among them, the mass fractions of the silane coupling agent and sodium carboxymethylcellulose dissolved in deionized water were 1.5 wt% and 0.1 wt% respectively; the viscosity of the aqueous phase W1 of the silica sol at room temperature was 500 mPa·s.

[0047] 2. At a solid-liquid ratio of 1:30, polyglycerol ricinoleate was dissolved in cyclohexane / liquid paraffin, and the volume ratio of cyclohexane to liquid paraffin was 3:1 to obtain the oil phase O. The aqueous phase W1 of the silica sol and the oil phase O were mixed at a mass ratio of 1:1 and homogenized at 12000 rpm for 20 min to form the W1 / O primary emulsion.

[0048] 3. A 2 wt% polyvinyl alcohol solution and a 0.4 wt% sodium dodecyl sulfate solution were mixed at a volume ratio of 1:1 and stirred at 300 rpm for 12 min to obtain the external aqueous phase W2. The W1 / O primary emulsion was injected into the external aqueous phase W2 at a mass ratio of (W1 / O):W2 = 1:5, and the reaction was carried out at 200 rpm and 20 °C for 3 h to form the W1 / O / W2 double emulsion.

[0049] 4. Add a 0.05 wt% tetraethoxysilane solution and a 0.02 wt% cetyltrimethylammonium bromide solution to the W1 / O / W2 double emulsion in a pulsed manner every 10 min at a mass ratio of 1:1. The total number of feedings is 6 times. Disperse ultrasonically at 300 W for 20 min and react at 40 °C for 6 h to obtain a silicon source solution. 5. Disperse and polymerize styrene in an anhydrous ethanol medium under a nitrogen atmosphere. Add dicyclohexylcarbodiimide and polyvinylpyrrolidone, stir and mix at 600 r / min for 20 min, then disperse ultrasonically at 300 W for 5 min, and then stir and react at 70 °C and 120 r / min for 24 h. After centrifugal separation, wash with anhydrous ethanol and distilled water, and dry at 60 °C for 2 h to obtain styrene seeds. Among them, the mass ratio of polymerized styrene to anhydrous ethanol is 1:60; the addition amounts of dicyclohexylcarbodiimide and polyvinylpyrrolidone are 5 wt% and 1 wt% of polymerized styrene, respectively.

[0050] 6. Disperse the styrene seeds in deionized water at a solid-liquid ratio of 1:60, add benzoyl peroxide and polyvinyl alcohol, disperse ultrasonically at 300 W for 5 min, and then stir in a water bath at 30 °C for 30 min to obtain a styrene seed suspension. Among them, the mass ratio of styrene seeds, benzoyl peroxide and polyvinyl alcohol is 1:0.2:3.

[0051] 7. Dissolve glycidyl methacrylate, ethylene dimethacrylate and cyclohexanol in deionized water, mix evenly and emulsify for 30 min to obtain an emulsified mixture. Add the emulsified mixture to the styrene seed suspension at a volume ratio of 1:2, react in a water bath at 70 °C for 24 h, wash the obtained microspheres with water, remove cyclohexanol by toluene extraction, and dry at 50 °C for 6 h to obtain glycidyl methacrylate co-ethylene dimethacrylate microspheres. Among them, the mass ratio of glycidyl methacrylate, ethylene dimethacrylate and cyclohexanol is 1:1:2.

[0052] 8. Mix the obtained glycidyl methacrylate co-ethylene dimethacrylate microspheres with isopropanol and deionized water at a mass ratio of 1:20:4, and perform ultrasonic treatment at 600 W for 15 min to obtain a glycidyl methacrylate co-ethylene dimethacrylate microsphere solution.

[0053] 9. Under a nitrogen atmosphere, at a dropping rate of 0.2 mL / min, the silicon source solution was dropped into the poly(glycidyl methacrylate)-co-ethylene glycol dimethacrylate microsphere solution. 0.1 M ammonia water was added dropwise to adjust the pH to 5.5, and the mixture was stirred at 30 °C for 2 h and then vacuum infiltrated for 30 min. The obtained microspheres were washed with deionized water and then subjected to segmented calcination: first, heated to 280 °C at a rate of 2 °C / min and held for 1 h, then heated to 500 °C at a rate of 5 °C / min and cured for 2 h. After calcination, the obtained microspheres were subjected to CO2 supercritical drying and dried at 10 MPa and 45 °C for 3 h to obtain the initial mesoporous silica microspheres. Among them, the mass ratio of the poly(glycidyl methacrylate)-co-ethylene glycol dimethacrylate microsphere solution to the silicon source solution was 2:1.

[0054] 10. At a mass ratio of 1:25 and at 120 °C, the initial mesoporous silica microspheres were immersed in a 30 wt% hydrochloric acid solution for 6 h, then washed with deionized water until neutral, and then dried at 120 °C for 8 h. The obtained product was dispersed in toluene, octadecyltrichlorosilane was added, and the mixture was refluxed at 125 °C for 24 h. Finally, the obtained product was washed successively with toluene and ethanol and dried at 60 °C for 12 h to obtain mesoporous silica microspheres. At a solid-liquid ratio of 1:20, the mesoporous silica microspheres were dispersed in a toluene solution and loaded into a stainless steel column in a suspension manner at 40 MPa for high performance liquid chromatography. Among them, the mass ratio of octadecyltrichlorosilane to the initial mesoporous silica microspheres was 1:1.

[0055] The difference between Comparative Example 2 and Example 1 is that the mesoporous silica microspheres were not modified with octadecyltrichlorosilane, and the specific steps are as follows: 1. The silane coupling agent and sodium carboxymethylcellulose were dissolved in deionized water and ultrasonic dispersed at 600 W for 30 min to obtain the aqueous phase W1 of the silicon solution. Among them, the mass fractions of the silane coupling agent and sodium carboxymethylcellulose dissolved in deionized water were 1.5 wt% and 0.1 wt% respectively; the viscosity of the aqueous phase W1 of the silicon solution at room temperature was 500 mPa·s.

[0056] 2. At a solid-liquid ratio of 1:30, polyglycerol ricinoleate was dissolved in cyclohexane / liquid paraffin, and the volume ratio of cyclohexane to liquid paraffin was 3:1 to obtain the oil phase O. The aqueous phase W1 of the silicon solution and the oil phase O were mixed at a mass ratio of 1:1 and homogenized at 12000 rpm for 20 min to form the W1 / O primary emulsion.

[0057] 3. A 2 wt% polyvinyl alcohol solution and a 0.4 wt% sodium dodecyl sulfate solution were mixed at a volume ratio of 1:1 and stirred at 300 rpm for 12 min to obtain the outer aqueous phase W2. According to the mass ratio (W1 / O):W2 = 1:5, the outer aqueous phase W2 was added to the W1 / O primary emulsion, and the reaction was carried out at 200 rpm and 20 °C for 3 h to form the W1 / O / W2 double emulsion.

[0058] 4. Add a 0.05 wt% tetraethoxysilane solution and a 0.02 wt% cetyltrimethylammonium bromide solution to the W1 / O / W2 double emulsion in a mass ratio of 1:1 in a pulsed manner every 10 min. The total number of feeding times is 6 times. Disperse it with ultrasonic waves at 300 W for 20 min and react at 40 °C for 6 h to obtain a silicon source solution. 5. Under a nitrogen atmosphere, disperse and polymerize styrene in an absolute ethanol medium. Add dicyclohexylcarbodiimide and polyvinylpyrrolidone. After stirring and mixing at 600 r / min for 20 min, disperse it with ultrasonic waves at 300 W for 5 min, and then stir and react at 70 °C and 120 r / min for 24 h. After centrifugal separation, wash it with absolute ethanol and distilled water, and dry it at 60 °C for 2 h to obtain styrene seeds. Among them, the mass ratio of polymerized styrene to absolute ethanol is 1:60; the addition amounts of dicyclohexylcarbodiimide and polyvinylpyrrolidone are 5 wt% and 1 wt% of polymerized styrene, respectively.

[0059] 6. Disperse the styrene seeds in deionized water at a solid-liquid ratio of 1:60. Add benzoyl peroxide and polyvinyl alcohol. After dispersing with ultrasonic waves at 300 W for 5 min, stir it in a 30 °C water bath for 30 min to obtain a styrene seed suspension. Among them, the mass ratio of styrene seeds, benzoyl peroxide and polyvinyl alcohol is 1:0.2:3.

[0060] 7. Dissolve glycidyl methacrylate, ethylene dimethacrylate and cyclohexanol in deionized water, mix them evenly and emulsify for 30 min to obtain an emulsified mixture. Add the emulsified mixture to the styrene seed suspension in a volume ratio of 1:2 and react in a 70 °C water bath for 24 h. Wash the obtained microspheres with water, remove cyclohexanol by toluene extraction, and dry at 50 °C for 6 h to obtain glycidyl methacrylate co-ethylene glycol dimethacrylate microspheres. Among them, the mass ratio of glycidyl methacrylate, ethylene dimethacrylate and cyclohexanol is 1:1:2.

[0061] 8. Disperse the glycidyl methacrylate co-ethylene glycol dimethacrylate microspheres in deionized water at a mass ratio of 1:40. Treat them with ultrasonic waves at 600 W for 5 min, add tetraethylenepentamine, and react at 80 °C for 12 h. After the reaction, wash them and dry at 60 °C for 3 h. Mix the dried microspheres with isopropanol and deionized water, and treat them with ultrasonic waves at 600 W for 15 min to obtain a modified glycidyl methacrylate co-ethylene glycol dimethacrylate microsphere solution. Among them, the mass ratio of glycidyl methacrylate co-ethylene glycol dimethacrylate microspheres to tetraethylenepentamine is 1:2; the mass ratio of the dried microspheres to isopropanol and deionized water is 1:20:4.

[0062] 9. Under a nitrogen atmosphere, the silicon source solution was dropped into the modified poly(glycidyl methacrylate) co-ethylene glycol dimethacrylate microsphere solution at a dropping rate of 0.2 mL / min. 0.1 M ammonia water was added dropwise to adjust the pH to 5.5, and the mixture was stirred and reacted at 30 °C for 2 h, followed by vacuum infiltration for 30 min. The obtained microspheres were washed with deionized water and then subjected to staged calcination: first heated to 280 °C at a rate of 2 °C / min and held for 1 h, then heated to 500 °C at a rate of 5 °C / min and cured for 2 h. After calcination, the obtained microspheres were subjected to CO2 supercritical drying at 10 MPa and 45 °C for 3 h to obtain mesoporous silica microspheres. Among them, the mass ratio of the modified poly(glycidyl methacrylate) co-ethylene glycol dimethacrylate microsphere solution to the silicon source solution was 2:1.

[0063] 10. According to the solid-liquid ratio of 1:20, the mesoporous silica microspheres were dispersed in toluene solution and loaded into a stainless steel column in the form of a suspension at 40 MPa for high performance liquid chromatography.

[0064] Figure 1 Figure 1 is the particle size distribution diagram of the mesoporous silica microspheres obtained in different examples. Among them, curves a, b, c, d, and e are the particle size distribution curves of the mesoporous silica microspheres obtained in Comparative Example 1, Comparative Example 2, Example 1, Example 2, and Example 3, respectively. It can be seen from Figure 1 this that compared with Comparative Examples 1-2, in Examples 1-3, the peak of the particle size distribution curve is concentrated, the particle size is highly uniform, and the dispersibility is good; while in the comparative examples, although the particle size distribution is also a single peak, the particle size curve is widely distributed, with a large span and a large particle size difference, resulting in poor dispersibility.

[0065] Figure 2 Figure 2 is the scanning electron microscope image of the mesoporous silica microspheres obtained in different examples. Among them, Figure a is the scanning electron microscope image of the mesoporous silica microspheres obtained in Comparative Example 1; Figure b is the scanning electron microscope image of the mesoporous silica microspheres obtained in Comparative Example 2; Figure c is the scanning electron microscope image of the mesoporous silica microspheres obtained in Example 1. The overall particle size of the mesoporous silica microspheres obtained in Comparative Examples 1-2 is relatively large and unevenly distributed, and a small part of the silica microspheres shows adhesion; the mesoporous silica microspheres obtained in Example 1 are more uniformly distributed and basically have no adhesion phenomenon, and the dispersibility is greatly improved.

[0066] The yields of the mesoporous silica microspheres in different examples were determined by TG / DSC and calculated according to the mass of the product after calcination / the theoretical maximum mass. The calculation results are shown in Table 1: Table 1 Mesoporous silica formation rate

[0067] Four amino branches of tetraethylenepentamine are connected to the epoxy groups on the surface of poly(glycidyl methacrylate)-co-ethylene glycol dimethacrylate microspheres through multi-point anchoring to form a "lying" graft configuration, which improves the pore openness on the surface of the template microspheres, increases the diffusion flux of the silicon source, and improves the formation rate of mesoporous silica microspheres. In Comparative Example 1, the modification with tetraethylenepentamine is absent, and the formation rate of mesoporous silica is significantly reduced.

[0068] An HPLC accelerated aging test was set up. The chromatographic column was 15 cm × 4.6 mm, filled with the mesoporous silica microspheres obtained from different examples. The mobile phase was acetonitrile / water = 50:50, the flow rate was 1 mL / min, and the number of injection cycles was 200 times. The test results are shown in Table 2.

[0069] Table 2 Results of HPLC accelerated aging experiment

[0070] By functionalizing mesoporous silica microspheres with octadecyltrichlorosilane, the exposure of silanol groups can be effectively reduced, and the non-specific adsorption with the sample for separation and purification can be decreased. Therefore, the loss of column efficiency in Examples 1-3 is significantly reduced, while in Comparative Example 2, due to the absence of modification with octadecyltrichlorosilane, the loss of column efficiency is significantly increased.

[0071] The specific embodiments of the present invention described above do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and deformations made according to the technical concept of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. A method for preparing mesoporous silica microspheres, comprising the following steps: S1. Mix the aqueous phase W1 of silica sol and the oil phase O at a mass ratio of 1:1, and form a primary W1 / O emulsion by high-speed homogenization; then inject the primary W1 / O emulsion into the external aqueous phase W2 at a mass ratio of (W1 / O):W2 = 1:5, and homogenize at 200 rpm and 20 °C for 3 h to form a W1 / O / W2 double emulsion; S2. Pulse-add a 0.05-0.1 wt% tetraethoxysilane solution and a 0.02-0.08 wt% cetyltrimethylammonium bromide solution to the W1 / O / W2 double emulsion at a mass ratio of 1:1-2, disperse by ultrasonic wave at 300 W for 20 min, and react at 40 °C for 6 h to obtain a silicon source solution; S3. Under a nitrogen atmosphere, dropwise add the silicon source solution to the modified poly(glycidyl methacrylate)-co-ethylene glycol dimethacrylate microsphere solution at a dropping rate of 0.2 mL / min, adjust the pH to 5.5-6.5, stir and react at 30 °C for 2-4 h, and perform vacuum infiltration for 30-60 min. After the obtained microspheres are subjected to segmented calcination and drying, initial mesoporous silica microspheres are obtained; wherein, the mass ratio of the modified poly(glycidyl methacrylate)-co-ethylene glycol dimethacrylate microsphere solution to the silicon source solution is 2:1-3; S4. At a mass ratio of 1:25 and at 120 °C, soak the initial mesoporous silica microspheres in a 30 wt% hydrochloric acid solution for 6 h, wash and dry them, disperse them in toluene, add octadecyltrichlorosilane, reflux at 125 °C for 24 h, and finally wash the obtained product with toluene and ethanol in sequence, and dry it to obtain mesoporous silica microspheres; wherein, the mass ratio of octadecyltrichlorosilane to the initial mesoporous silica microspheres is 1:

1.

2. The preparation method of a mesoporous silica microsphere according to claim 1, wherein, In step S1, the preparation method of the aqueous phase W1 of silica sol is: dissolve a silane coupling agent and sodium carboxymethylcellulose in deionized water, and disperse by ultrasonic wave at 600 W for 30 min; wherein, the mass fractions of the silane coupling agent and sodium carboxymethylcellulose dissolved in deionized water are 1.5-2.0 wt% and 0.1-0.5 wt% respectively, and the viscosity of the aqueous phase of silica sol is 500-800 mPa·s at room temperature.

3. The preparation method of a mesoporous silica microsphere according to claim 1, wherein In step S1, the preparation method of the oil phase O is: dissolve polyglycerol ricinoleate in cyclohexane / liquid paraffin at a solid-liquid ratio of 1:30, and the volume ratio of cyclohexane to liquid paraffin is 3:1; the preparation method of the external aqueous phase W2 is: mix a 2 wt% polyvinyl alcohol solution and a 0.4 wt% sodium dodecyl sulfate solution at a volume ratio of 1:1, and stir at 300 rpm for 12 min.

4. The preparation method of a mesoporous silica microsphere according to claim 1, characterized in that In step S2, the dropping method of the tetraethoxysilane solution and the cetyltrimethylammonium bromide solution is pulse dropping: alternately add the tetraethoxysilane solution and the cetyltrimethylammonium bromide solution every 10 min, and the total number of feeding times is 6-10 times.

5. The preparation method of a mesoporous silica microsphere according to claim 1, characterized in that, In step S3, the preparation method of the modified poly (glycidyl methacrylate-co-ethylene glycol dimethacrylate) microsphere solution is as follows: disperse poly (glycidyl methacrylate-co-ethylene glycol dimethacrylate) microspheres in deionized water, add tetraethylenepentamine after ultrasonic treatment, react at 80 °C for 12 h, wash and dry after the reaction; mix the dried microspheres with isopropanol and deionized water, and perform ultrasonic treatment at 600 W for 15 min to obtain the modified poly (glycidyl methacrylate-co-ethylene glycol dimethacrylate) microsphere solution; wherein, the mass ratio of poly (glycidyl methacrylate-co-ethylene glycol dimethacrylate) microspheres to tetraethylenepentamine is 1:2 - 4; the mass ratio of the dried microspheres to isopropanol and deionized water is 1:20:

4.

6. The preparation method of a mesoporous silica microsphere according to claim 5, characterized in that, The preparation method of the poly (methacrylate-co-ethylene glycol dimethacrylate) microspheres is as follows: dissolve glycidyl methacrylate, ethylene dimethacrylate and cyclohexanol in deionized water, mix evenly and emulsify for 30 min to obtain an emulsified mixture; add the emulsified mixture into a styrene seed suspension, react in a 70 °C water bath for 24 h, wash the obtained microspheres with water, remove cyclohexanol by toluene extraction, and dry at 50 °C for 6 h to obtain poly (glycidyl methacrylate-co-ethylene glycol dimethacrylate) microspheres; wherein, the mass ratio of glycidyl methacrylate, ethylene dimethacrylate and cyclohexanol is 1:1 - 3:

2.

7. The preparation method of a mesoporous silica microsphere according to claim 6, characterized in that, The preparation method of the styrene seed suspension is as follows: under a nitrogen atmosphere, disperse-polymerize styrene in an anhydrous ethanol medium, add dicyclohexylcarbodiimide and polyvinylpyrrolidone, mix evenly and then perform ultrasonic treatment, and then stir and react at 70 °C and 120 r / min for 24 h, centrifuge and separate, wash, and dry to obtain styrene seeds; Disperse the styrene seeds in deionized water, add benzoyl peroxide and polyvinyl alcohol, perform ultrasonic dispersion, and then stir in a 30 °C water bath for 30 min to obtain a styrene seed suspension; wherein, the addition amounts of dicyclohexylcarbodiimide and polyvinylpyrrolidone are 5 wt% and 1 wt% of the polymerized styrene respectively; the mass ratio of styrene seeds, benzoyl peroxide and polyvinyl alcohol is 1:0.2 - 0.5:

3.

8. Mesoporous silica microspheres prepared by the preparation method of the mesoporous silica microspheres described in claim 1.

9. Use of the mesoporous silica microspheres prepared by the preparation method of the mesoporous silica microspheres according to claim 1 in high performance liquid chromatography, characterized in that, Disperse the mesoporous silica microspheres in a toluene solution according to a solid-liquid ratio of 1:20, and load them into a stainless steel column in a suspension manner at 40 MPa for high performance liquid chromatography.

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