【摘要】 对比研究了微量CaCl2电解质对直接法生长和以种子法生长制备二氧化硅微球的影响。随着CaCl2加入量的增加,两种制备途径所得球体粒径的大小和分散度都出现明显变化,当Ca2+的浓度达到3.3mmol/L时,颗粒已不能保持球体形状,开始成絮状物。通过对结果的对比分析,为理解二氧化硅球体生长机理提供了帮助。更多还原

【Abstract】 Electrolyte CaCl₂ was added to the reaction system during the formation of silica spheres in order to study the electrolyte effect.It has been shown that the addation of a trace of CaCl₂ can modify the growth mechanism of the spheres.The high concentration electrolyte reduced the value of Ck（critical nucleation concentration）,which makes the creation of nuclei easier and provokes the competition between the nuclei formation and the sphere growth.When the concentration of the Ca2+ reached to a value of 3.3mmol/L,the particles lost their sphere shape and aggregations were obtained.更多还原