分散剂对亚微米级球形SiO_2微粒制备的影响

Effect of dispersant on the preparation of sub-micron spherical SiO_2 particles

采用溶胶-凝胶法，以氨水为催化剂、醇水混合物为溶剂、硅烷偶联剂为表面分散剂，通过正硅酸乙酯（TEOS）的水解缩合制备单分散的亚微米级二氧化硅（SiO2）微球。着重研究了硅烷偶联剂的用量及滴加顺序对SiO2颗粒粒径的影响，通过扫描电镜（SEM）对颗粒的形貌进行表征。结果表明：在反应温度为室温（20℃），正硅酸乙酯浓度为0．2～0.3mol／L，静置反应后添加0．075～0．125mL分散剂的条件下可制备出300～600nm的SiO2微球。在室温（20℃），正硅酸乙酯浓度为0.3mol／L，静置反应后添加0．075～0．125mL分散剂的条件下，更有利于SiO2微球的长大，制各得颗粒粒径约600nnl的亚微米级SiO2微球。

The monodisperse submicron silica microspheres were successfully prepared by sol-gel method. Ammo- nia was used as catalyst, mixture of alcohol and water was employed as solvent, and silane coupling agent was used as surfactant. The influence of silane coupling agent dosage and the order added to the solution on particle size were studied. The morphology of the particles was characterized by scanning electron microscope （SEM）. The experimental results show that, under the reaction temperature of 20 ℃, ethyl orthosilicate concentration of 0.2-0.3 mol/L, and the dispersant of 0.075-0.125 mL added after the incubation reaction, the silica microspheres of 300-600 nm are prepared. And at room temperature of 20 ℃, ethyl orthosilicate concentration of 0.3 mol/L, 0.075-0.125 mL dispersant added after the incubation reaction, the silica particles grow up more easily to silica mi- crospheres of about 600 nm.