Preparation And Characterization Of Monodisperse Large Size Silica Microspheres

In this paper,the application prospects of microspheres are reviewed,and the preparation process and applications of polystyrene and silica microspheres are detailed.Non-porous silica microspheres,porous silica microspheres and core-shell silica microspheres were successfully synthesized by three preparation methods.The effects of experimental temperature,ammonia addition,silicon source addition and drop acceleration on the morphology and particle size of silica microspheres were investigated,and BET,IR and XRD characterizations of silica microspheres were performed.With the increase of reaction temperature,the particle size of silica microspheres tended to decrease and was most uniform at 40℃.The addition of ammonia would increase the particle size of silica microspheres in a certain range,and the addition of tetraethyl orthosilicate was also the main factor affecting the particle size.Porous silica microspheres with rounded morphology,particle size below 10μm,specific surface area of 396.5281 m²/g,pore volume of 1.023023 cm³/g,and average pore size of 10.1644 nm were successfully prepared by a two-step sol-gel method.The effects of acid dosage,spin temperature,stirring speed,ammonia dosage,emulsifying porogenic agent type,emulsifying porogenic agent dosage,and post-treatment method on the silica microspheres were investigated.When the n（HCl）:n（TEOS）=3:2,the silica microspheres were prepared with 41.56%PES silica content,46.3 m Pa·s viscosity,56℃ spin temperature,2000 r/min mechanical stirring speed,DMF as emulsifying pore-making agent,and 475μL addition amount,and the porosity was basically the same as that of the commercial silica microspheres.microspheres with the same porosity as commercial silica microspheres.Monodisperse cationic polystyrene microspheres with a particle size of 900 nm were successfully prepared by dispersion polymerization,and PS@Si O₂ core-shell silica microspheres with a particle size of 1μm and a shell layer thickness of 50 nm were successfully prepared by sol-gel method using polystyrene microspheres as a template.The microspheres were characterized by SEM,TEM,Zeta potential,EDS,TG,and IR.The effects of dispersant dosage,styrene dosage,initiator dosage on PS microspheres and the effects of ammonia dosage and TEOS dosage on silica microspheres were discussed.