Preparation of Nano-SiO2 Microspheres and Study on Their Structure and Properties
With dodecyl trimethylammonium bromide(CTAB)as the surfactant,aqueous ammonia as the catalyst,and tetraethoxy silane(TEOS)as the precursor,nano-silica microspheres were prepared in an ethanol/water mixed solvent by the simple ammonia catalytic hydrolysis method.The morphology and particle size of the samples were characterized using scanning electron microscopy(SEM).The results showed that,under constant conditions,the particle size of the SiO2 microspheres gradually increased and the particle size distribution widened with an increase in the amount of CTAB.Additionally,with a decrease in the alcohol-to-water ratio and an increase in TEOS dosage and ammonia concentration,the particle size of the SiO2 microspheres initially increased and then decreased.However,the particle size distribution initially widened and then narrowed with the decrease in the ratio of alcohol to water,while an increase in TEOS dosage initially narrowed and then widened the particle size distribution.Moreover,an increase in ammonia concentration led to a gradual widening of the particle size distribution of the SiO2 microspheres.The optimum alcohol-to-water ratio for preparing SiO2 microspheres was 0.6∶1,resulting in well-dispersed microspheres with a narrow particle size distribution and an average particle size of 533 nm.Further studies concluded that CTAB and ethanol interact in the"oil in water"system in the deionized water system.The optical properties(transmittance at 76.06％and haze at 48.35％)of the microspheres after film formation meet the practical application,indicating their potential application value in the anti-glare and anti-reflection fields of the display screen.
NETL
NSTL
万方数据
